Phase tracking reference signal (PT-RS) configuration

ABSTRACT

A user equipment (UE) can include processing circuitry configured to decode downlink control information (DCI) from a base station, the DCI including a modulation coding scheme (MCS) index and physical uplink shared channel (PUSCH) allocation. A demodulation reference signal (DM-RS) is encoded for transmission to the base station within a plurality of DM-RS symbols based on the PUSCH allocation. A phase tracking reference signal (PT-RS) time domain density is determined based on the MCS index and a number count of the DM-RS symbols for the DM-RS transmission. The PT-RS is encoded for transmission using a plurality of PT-RS symbols based on the determined time domain density. The plurality of symbols includes one or both of front-loaded DM-RS symbols and additional DM-RS symbols.

PRIORITY CLAIM

This application claims the benefit of priority to the followingapplications: PCT Application Serial No. PCT/CN2017/100926, filed Sep.7, 2017, and entitled “PHASE TRACKING REFERENCE SIGNAL CONFIGURATION;”PCT Application Serial No. PCT/CN2017/111058, filed Nov. 15, 2017, andentitled “PHASE TRACKING REFERENCE SIGNAL (PTRS) PATTERN IN ADAPTIVEHYBRID AUTOMATIC REPEAT REQUEST (HARQ);” and U.S. Provisional PatentApplication Ser. No. 62/587,910, filed Nov. 17, 2017, and entitled“RESOURCE MAPPING OF PHASE TRACKING REFERENCE SIGNAL (PT-RS).”

Each of the above-identified patent applications is incorporated. hereinby reference in its entirety.

TECHNICAL FIELD

Aspects pertain to wireless communications. Some aspects relate towireless networks including 3GPP (Third Generation Partnership Project)networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (LTEAdvanced) networks, and fifth-generation (5G) networks including 5G newradio (NR) (or 5G-NR) networks and 5G-LTE networks. Other aspects aredirected to systems and methods for phase tracking reference signal(PT-RS) configuration. Additional aspects are directed to PT-RS patternconfiguration in adaptive hybrid automatic repeat request (HARQ)process. Yet other aspects are directed to resource mapping of PT-RS.

BACKGROUND

Mobile communications have evolved significantly from early voicesystems to today's highly sophisticated integrated communicationplatform. With the increase in different types of devices communicatingwith various network devices, usage of 3GPP LTE systems has increased.The penetration of mobile devices (user equipment or UEs) in modernsociety has continued to drive demand for a wide variety of networkeddevices in a number of disparate environments. Fifth generation (5G)wireless systems are forthcoming, and are expected to enable evengreater speed, connectivity, and usability. Next generation 5G networks(or NR networks) are expected to increase throughput, coverage, androbustness and reduce latency and operational and capital expenditures.5G-NR networks will continue to evolve based on 3GPP LTE-Advanced withadditional potential new radio access technologies (RATs) to enrichpeople's lives with seamless wireless connectivity solutions deliveringfast, rich content and services. As current cellular network frequencyis saturated, higher frequencies, such as millimeter wave (mmWave)frequency, can be beneficial due to their high bandwidth.

Potential LTE operation in the unlicensed spectrum includes (and is notlimited to) the LTE operation in the unlicensed spectrum via dualconnectivity (DC), or DC-based LAA, and the standalone LTE system in theunlicensed spectrum, according to which LTE-based technology solelyoperates in unlicensed spectrum without requiring an “anchor” in thelicensed spectrum, called MulteFire. MulteFire combines the performancebenefits of LTE technology with the simplicity of Wi-Fi-likedeployments.

Further enhanced operation of LTE systems in the licensed as well asunlicensed spectrum is expected in future releases and 5G systems. Suchenhanced operations can include techniques to address configuration ofPT-RS, including determining PT-RS time domain and frequency domaindensity as well as resource mapping for PT-RS.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The figures illustrate generally, by way of example, but notby way of limitation, various aspects discussed in the present document.

FIG. 1A illustrates an architecture of a network in accordance with someaspects.

FIG. 1B is a simplified diagram of an overall next generation (NG)system architecture in accordance with some aspects.

FIG. 1C illustrates an example MulteFire Neutral Host Network (NHN) 5Garchitecture in accordance with some aspects.

FIG. 1D illustrates a functional split between next generation radioaccess network (NG-RAN) and the 5G Core network (5GC) in accordance withsome aspects.

FIG. 1E and FIG. 1F illustrate a non-roaming 5G system architecture inaccordance with some aspects.

FIG. 1G illustrates an example Cellular Internet-of-Things (CIoT)network architecture in accordance with some aspects.

FIG. 1H illustrates an example Service Capability Exposure

Function (SCEF) in accordance with some aspects.

FIG. 1I illustrates an example roaming architecture for SCEF inaccordance with some aspects.

FIG. 1J illustrates an example Evolved Universal Terrestrial RadioAccess (E-UTRA) New Radio Dual Connectivity (EN-DC) architecture inaccordance with some aspects.

FIG. 2 illustrates example components of a device 200 in accordance withsome aspects.

FIG. 3 illustrates example interfaces of baseband circuitry inaccordance with some aspects.

FIG. 4 is an illustration of a control plane protocol stack inaccordance with some aspects.

FIG. 5 is an illustration of a user plane protocol stack in accordancewith some aspects.

FIG. 6 is a block diagram illustrating components, according to someexample aspects, able to read instructions from a machine-readable orcomputer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein.

FIG. 7 is an illustration of an initial access procedure including PRACHpreamble retransmission in accordance with some aspects.

FIG. 8 illustrates an example of chunk-based PT-RS for a digital Fouriertransform (DFT) spread orthogonal frequency division multiplexing(DFT-s-OFDM) waveform, in accordance with some aspects.

FIG. 9 illustrates an example slot with PT-RS and DM-RS symbolcollision, in accordance with some aspects.

FIG. 10 illustrates an example slot with PT-RS collision handling usingPT-RS puncturing, in accordance with some aspects.

FIG. 11 illustrates an example slot with PT-RS collision handling usinga resource element shifting, in accordance with some aspects.

FIG. 12 illustrates an example slot with PT-RS collision handling usingshifting of multiple resource elements, in accordance with some aspects.

FIG. 13 illustrates an example slot with PT-RS multiplexing when anadditional DM-RS symbol is used, in accordance with some aspects.

FIG. 14 illustrates example PT-RS time domain pattern determination fortwo codewords and one PT-RS antenna port, in accordance with someaspects.

FIG. 15 illustrates example PT-RS time domain pattern determination fortwo codewords and two PT-RS antenna ports, in accordance with someaspects.

FIG. 16 illustrates example PT-RS time domain pattern determination fortwo codewords and two PT-RS antenna ports, in accordance with someaspects.

FIG. 17 illustrates example PT-RS time domain pattern determination fora single codewords and two PT-RS antenna ports, in accordance with someaspects.

FIG. 18 illustrates an example slot with PT-RS and tracking referencesignal (TRS) collision, in accordance with some aspects.

FIG. 19 illustrates generally a flowchart of example functionalitieswhich can be performed in a wireless architecture in connection withPT-RS configuration, in accordance with some aspects.

FIG. 20 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a new generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or a userequipment (UE), in accordance with some aspects.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrateaspects to enable those skilled in the art to practice them. Otheraspects may incorporate structural, logical, electrical, process, andother changes. Portions and features of some aspects may be included in,or substituted for, those of other aspects. Aspects set forth in theclaims encompass all available equivalents of those claims.

FIG. 1A illustrates an architecture of a network in accordance with someaspects. The network 140A is shown to include a user equipment (UE) 101and a UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g.,handheld touchscreen mobile computing devices connectable to one or morecellular networks), but may also comprise any mobile or non-mobilecomputing device, such as Personal Data Assistants (PDAs), pagers,laptop computers, desktop computers, wireless handsets, drones, or anyother computing device including a wired and/or wireless communicationsinterface.

Any of the radio links described herein (e.g., as used in the network140A or any other illustrated network) may operate according to any oneor more of the following exemplary radio communication technologiesand/or standards including, but not limited to: a Global System forMobile Communications (GSM) radio communication technology, a GeneralPacket Radio Service (GPRS) radio communication technology, an EnhancedData Rates for GSM Evolution (EDGE) radio communication technology,and/or a Third Generation Partnership Project (3GPP) radio communicationtechnology, for example Universal Mobile Telecommunications System(UMTS), Freedom of Multimedia Access (FOMA), 3GPP Long Term Evolution(LTE), 3GPP Long Term Evolution Advanced (LTE Advanced), Code divisionmultiple access 2000 (CDMA2000), Cellular Digital Packet Data (CDPD),Mobitex, Third. Generation (3G), Circuit Switched Data (CSD), High-SpeedCircuit-Switched Data (HSC SD), Universal Mobile TelecommunicationsSystem (Third Generation) (UMTS (3G)), Wideband Code Division MultipleAccess (Universal Mobile Telecommunications System) (W-CDMA (UNITS)),High Speed Packet Access (HSPA), High-Speed Downlink Packet Access(HSDPA), High-Speed Uplink Packet Access (HSUPA), High Speed PacketAccess Plus (HSPA+), Universal Mobile TelecommunicationsSystem-Time-Division Duplex (UMTS-TDD), Time Division-Code DivisionMultiple Access (TD-CDMA), Time Division-Synchronous Code DivisionMultiple Access (TD-CDMA), 3rd Generation Partnership Project Release 8(Pre-4th Generation) (3GPP Rel. 8 (Pre-4G)), 3GPP Rel. 9 (3rd GenerationPartnership Project Release 9), 3GPP Rel. 10 (3rd Generation PartnershipProject Release 10), 3GPP Rel. 11 (3rd Generation Partnership ProjectRelease 11), 3GPP Rel. 12 (3rd Generation Partnership Project Release12), 3GPP Rel. 13 (3rd Generation Partnership Project Release 13), 3GPPRel. 14 (3rd Generation Partnership Project Release 14), 3GPP Rel. 15(3rd Generation Partnership Project Release 15), 3GPP Rel. 16 (3rdGeneration Partnership Project Release 16), 3GPP Rel. 17 (3rd GenerationPartnership Project Release 17), 3GPP Rel. 18 (3rd GenerationPartnership Project Release 18), 3GPP 5G or 5G-NR, 3GPP LTE Extra,LTE-Advanced Pro, LTE Licensed-Assisted. Access (LAA), MulteFire, UMTSTerrestrial Radio Access (UTRA), Evolved UMTS Terrestrial Radio Access(E-UTRA), Long Term Evolution Advanced (4th Generation) (LTE Advanced(4G)), cdmaOne (2G), Code division multiple access 2000 (Thirdgeneration) (CDMA2000 (3G)), Evolution-Data Optimized or Evolution-DataOnly (EV-DO), Advanced Mobile Phone System (1st Generation) (AMPS (1G)),Total Access Communication System/Extended Total Access CommunicationSystem (TACS/ETACS), Digital AMPS (2nd Generation) (D-AMPS (2G)),Push-to-talk (PTT), Mobile Telephone System (MTS), improved MobileTelephone System (INITS), Advanced Mobile Telephone System (AMTS), OLT(Norwegian for Offentlig Landmobil Telefoni, Public Land MobileTelephony), CIoTD (Swedish abbreviation for Mobiltelefonisystem D, orMobile telephony system D), Public Automated Land Mobile (Autotel/PALM),ARP (Finnish for Autoradiopuhelin, “car radio phone”), NMT (NordicMobile Telephony), High capacity version of NTT (Nippon Telegraph andTelephone) (Hicap), Cellular Digital Packet Data (CDPD), Mobitex,DataTAC, Integrated Digital Enhanced Network (iDEN), Personal DigitalCellular (PDC), Circuit Switched. Data (CSD), Personal Handy-phoneSystem (PHS), Wideband Integrated Digital Enhanced Network (WiDEN),iBurst, Unlicensed Mobile Access (UMA), also referred to as alsoreferred to as 3GPP Generic Access Network, or GAN standard), Zigbee,Bluetooth(r), Wireless Gigabit Alliance (WiGig) standard, mmWavestandards in general (wireless systems operating at 10-300 GHz and abovesuch as WiGig, IEEE 802.11 ad, IEEE 802.11ay, and the like),technologies operating above 300 GHz and THz bands, (3GPP/LTE based orIEEE 802.11p and other), Vehicle-to-Vehicle (V2V), Vehicle-to-X (V2X),Vehicle-to-Infrastructure (V2I), and Infrastructure-to-Vehicle (I2V)communication technologies, 3GPP cellular V2X, DSRC (Dedicated ShortRange Communications) communication systems such asIntelligent-Transport-Systems and others.

LTE and LTE-Advanced are standards for wireless communications ofhigh-speed data for user equipment (UE) such as mobile telephones. InLTE-Advanced and various wireless systems, carrier aggregation is atechnology according to which multiple carrier signals operating ondifferent frequencies may be used to carry communications for a singleLTE, thus increasing the bandwidth available to a single device. In someaspects, carrier aggregation may be used where one or more componentcarriers operate on unlicensed frequencies.

There are emerging interests in the operation of LTE systems in theunlicensed spectrum. As a result, an important enhancement for LTE in3GPP Release 13 has been to enable its operation in the unlicensedspectrum via Licensed-Assisted Access (LAA), which expands the systembandwidth by utilizing the flexible carrier aggregation (CA) frameworkintroduced by the LTE-Advanced system. Rel-13 LAA system focuses on thedesign of downlink operation on unlicensed spectrum via CA, while Rel-14enhanced. LAA (eLAA) system focuses on the design of uplink operation onunlicensed spectrum via CA.

Aspects described herein can be used in the context of any spectrummanagement scheme including, for example, dedicated licensed spectrum,unlicensed spectrum, (licensed) shared spectrum (such as Licensed SharedAccess (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz and furtherfrequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and furtherfrequencies). Applicable exemplary spectrum bands include IMT(International Mobile Telecommunications) spectrum (including 450-470MHz, 790-960 MHz, 1710-2025 MHz, 2110-2200 MHz, 2300-2400 MHz, 2500-2690MHz, 698-790 MHz, 610-790 MHz, 3400-3600 MHz, to name a few),IMT-advanced spectrum, IMT-2020 spectrum (expected to include 3600-3800MHz, 3.5 GHz bands, 700 MHz bands, bands within the 24.25-86 GHz range,for example), spectrum made available under the Federal CommunicationsCommission's “Spectrum Frontier” 5G initiative (including 27.5-28.35GHz, 29.1-29.25 GHz, 31-31.3 GHz, 37-38.6 GHz, 38.6-40 GHz, 42-42.5 GHz,57-64 GHz, 71-76 GHz, 81-86 GHz and 92-94 GHz, etc), the ITS(Intelligent Transport Systems) band of 5.9 GHz (typically 5.85-5.925GHz) and 63-64 GHz, bands currently allocated to WiGig such as WiGigBand 1 (57.24-59.40 GHz), WiGig Band 2 (59.40-61.56 GHz), WiGig Band 3(61.56-63.72 GHz), and WiGig Band 4 (63.72-65.88 GHz); the 70.2 GHz-71GHz band; any band between 65.88 GHZ and 71 GHz; bands currentlyallocated to automotive radar applications such as 76-81 GHz; and futurebands including 94-300 GHz and above. Furthermore, the scheme can beused on a secondary basis on bands such as the TV White Space bands(typically below 790 MHz) where in particular the 400 MHZ and 700 MHZbands can be employed. Besides cellular applications, specificapplications for vertical markets may be addressed, such as PMSE(Program Making and Special Events), medical, health, surgery,automotive, low-latency, drones, and the like.

Aspects described herein can also be applied to different Single Carrieror OFDM flavors (CP-OFDM. SC-FDMA, SC-OFDM, filter bank-basedmulticarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio)by allocating the OFDM carrier data bit vectors to the correspondingsymbol resources.

In some aspects, any of the UEs 101 and 102 can comprise anInternet-of-Things (IoT) UE or a Cellular IoT (CIoT) UE, which cancomprise a network access layer designed for low-power IoT applicationsutilizing short-lived UE connections. In some aspects, any of the UEs101 and 102 can include a narrowband (NB) IoT UE (e.g., such as anenhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoTIJE can utilize technologies such as machine-to-machine (M2M) ormachine-type communications (MTC) for exchanging data with an CIoTCserver or device via a public land mobile network (PLMN),Proximity-Based Service (ProSe) or device-to-device (D2D) communication,sensor networks, or IoT networks. The M2M or CIoTC exchange of data maybe a machine-initiated exchange of data. An IoT network includesinterconnecting IoT UEs, which may include uniquely identifiableembedded computing devices (within the Internet infrastructure), withshort-lived connections. The IoT UEs may execute background applications(e.g., keep-alive messages, status updates, etc.) to facilitate theconnections of the IoT network.

In some aspects, NB-IoT devices can be configured to operate in a singlephysical resource block (PRB) and may be instructed to retune twodifferent PRBs within the system bandwidth. In some aspects, an eNB-IoTUE can be configured to acquire system information in one PRB, and thenit can retune to a different PRB to receive or transmit data.

In some aspects, any of the UEs 101 and 102 can include enhanced CIoTC(eMTC) UEs or further enhanced CIoTC (FeMTC) UEs.

The UEs 101 and 102 may be configured to connect, es., communicativelycouple, with a radio access network (RAN) 110. The RAN 110 may be, forexample, an Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), orsome other type of RAN. The UEs 101 and 102 utilize connections 103 and104, respectively, each of which comprises a physical communicationsinterface or layer (discussed in further detail below); in this example,the connections 103 and 104 are illustrated as an air interface toenable communicative coupling, and can be consistent with cellularcommunications protocols, such as a Global System for MobileCommunications (GSM) protocol, a code-division multiple access (CDMA)network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular(POC) protocol, a Universal Mobile Telecommunications System (UMTS)protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation(5G) protocol, a New Radio (NR) protocol, and the like.

In some aspects, the network 140A can include a core network (CN) 120.Various aspects of NG RAN and NG Core are discussed herein in referenceto, e.g., FIG. 1B, FIG. 1C, FIG. 1D, FIG. 1E, FIG. 1F, and FIG. 1G.

In an aspect, the UEs 101 and 102 may further directly exchangecommunication data via a ProSe interface 105. The ProSe interface 105may alternatively be referred to as a sidelink interface comprising oneor more logical channels, including but not limited to a PhysicalSidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel(PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a PhysicalSidelink Broadcast Channel (PSBCH).

The UE 102 is shown to be configured to access an access point (AP) 106via connection 107. The connection 107 can comprise a local wirelessconnection, such as, for example, a connection consistent with any IEEE802.11 protocol, according to which the AP 106 can comprise a wirelessfidelity (WiFi®) router. In this example, the AP 106 is shown to beconnected to the Internet without connecting to the core network of thewireless system (described in further detail below).

The RAN 110 can include one or more access nodes that enable theconnections 103 and 104. These access nodes (ANs) can be referred to asbase stations (BSs), NodeBs, evolved NodeBs (eNBs), Next GenerationNodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations(e.g., terrestrial access points) or satellite stations providingcoverage within a geographic area (e.g., a cell). In some aspects, thecommunication nodes 111 and 112 can be transmission/reception points(TRPs). In instances when the communication nodes 111 and 112 are NodeBs(e.g., eNBs or gNBs), one or more TRPs can function within thecommunication cell of the NodeBs. The RAN 110 may include one or moreRAN nodes for providing macrocells, e.g., macro RAN node 111, and one ormore RAN nodes for providing femtocells or picocells (e.g., cells havingsmaller coverage areas, smaller user capacity, or higher bandwidthcompared to macrocells), e.g., low power (LP) RAN node 112.

Any of the RAN nodes 111 and 112 can terminate the air interfaceprotocol and can be the first point of contact for the UEs 101 and 102.In some aspects, any of the RAN nodes 111 and 112 can fulfill variouslogical functions for the RAN 110 including, but not limited to, radionetwork controller (RNC) functions such as radio bearer management,uplink and downlink dynamic radio resource management and data packetscheduling, and mobility management. In an example, any of the nodes 111and/or 112 can be a new generation node-B (gNB), an evolved node-B(eNB), or another type of RAN node.

In accordance with some aspects, the UEs 101 and 102 can be configuredto communicate using Orthogonal Frequency-Division Multiplexing (OFDM)communication signals with each other or with any of the RAN nodes 111and 112 over a multicarrier communication channel in accordance variouscommunication techniques, such as, but not limited to, an OrthogonalFrequency-Division Multiple Access (OFDMA) communication technique(e.g., for downlink communications) or a Single Carrier FrequencyDivision Multiple Access (SC-FDMA) communication technique (e.g., foruplink and ProSe for sidelink communications), although such aspects arenot required. The OFDM signals can comprise a plurality of orthogonalsubcarriers.

In some aspects, a downlink resource grid can be used for downlinktransmissions from any of the RAN nodes 111 and 112 to the UEs 101 and102, while uplink transmissions can utilize similar techniques. The gridcan be a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation may be used for OFDMsystems, which makes it applicable for radio resource allocation. Eachcolumn and each row of the resource grid may correspond to one OFDMsymbol and one OFDM subcarrier, respectively. The duration of theresource grid in the time domain may correspond to one slot in a radioframe. The smallest time-frequency unit in a resource grid may bedenoted as a resource element. Each resource grid may comprise a numberof resource blocks, which describe mapping of certain physical channelsto resource elements. Each resource block may comprise a collection ofresource elements; in the frequency domain, this may, in some aspects,represent the smallest quantity of resources that currently can beallocated. There may be several different physical downlink channelsthat are conveyed using such resource blocks.

The physical downlink shared channel (PDSCH) may carry user data andhigher-layer signaling to the LTEs 101 and 102. The physical downlinkcontrol channel (PDCCH) may carry information about the transport formatand resource allocations related to the PDSCH channel, among otherthings. It may also inform the UEs 101 and 102 about the transportformat, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request)information related to the uplink shared channel. Typically, downlinkscheduling (assigning control and shared channel resource blocks to theUE 102 within a cell) may be performed at any of the RAN nodes 111 and112 based on channel quality information fed. back from any of the UEs101 and 102. The downlink resource assignment information may be sent onthe PDCCH used for (e.g., assigned to) each of the UEs 101 and 102.

The PDCCH may use control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols may first be organized into quadruplets, whichmay then be permuted using a sub-block interleaver for rate matching.Each PDCCH may be transmitted using one or more of these CCEs, whereeach CCE may correspond to nine sets of four physical resource elementsknown as resource element groups (REGs). Four Quadrature Phase ShiftKeying (QPSK) symbols may be mapped to each REG. The PDCCH can betransmitted using one or more CCEs, depending on the size of thedownlink control information (DCI) and the channel condition. There canbe four or more different PDCCH formats defined in LTE with differentnumbers of CCEs (e.g., aggregation level, L=1, 2, 4, or 8).

Some aspects may use concepts for resource allocation for controlchannel information that are an extension of the above-describedconcepts. For example, some aspects may utilize an enhanced physicaldownlink control channel (EPDCCH) that uses PDSCH resources for controlinformation transmission. The EPDCCH may be transmitted using one ormore enhanced control channel elements (ECCEs). Similar to above, eachECCE may correspond to nine sets of four physical resource elementsknown as an enhanced resource element groups (EREGs). An ECCE may haveother numbers of EREGs according to some arrangements.

The RAN 110 is shown to be communicatively coupled to a core network(CN) 120 via an S1 interface 113. In aspects, the CN 120 may be anevolved packet core (EPC) network, a NextGen Packet Core (NPC) network,or some other type of CN (e.g., as illustrated in reference to FIGS.1B-1I). In this aspect, the S1 interface 113 is split into two parts:the S1-U interface 114, which carries traffic data between the RAN nodes111 and 112 and the serving gateway (S-GW) 122, and the S1-mobilitymanagement entity (MME) interface 115, which is a signaling interfacebetween the RAN nodes 111 and 112 and MMEs 121.

In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, thePacket Data Network (PDN) Gateway (P-GW) 123, and a home subscriberserver (HSS) 124. The MMEs 121 may be similar in function to the controlplane of legacy Serving General Packet Radio Service (GPRS) SupportNodes (SGSN). The MME's 121 may manage mobility aspects in access suchas gateway selection and tracking area list management. The HSS 124 maycomprise a database for network users, including subscription-relatedinformation to support the network entities' handling of communicationsessions. The CN 120 may comprise one or several HSSs 124, depending onthe number of mobile subscribers, on the capacity of the equipment, onthe organization of the network, etc. For example, the HSS 124 canprovide support for routing/roaming, authentication, authorization,naming/addressing resolution, location dependencies, etc.

The S-GW 122 may terminate the S1 interface 113 towards the RAN 110, androutes data packets between the RAN 110 and the CN 120. In addition, theS-GW 122 may be a local mobility anchor point for inter-RAN nodehandovers and also may provide an anchor for inter-3GPP mobility. Otherresponsibilities of the S-GW 122 may include lawful intercept, charging,and some policy enforcement.

The P-GW 123 may terminate a SGi interface toward a PDN. The P-GW 123may route data packets between the EPC network 120 and external networkssuch as a network including the application server 184 (alternativelyreferred to as application function (AF)) via an Internet Protocol (IP)interface 125. The P-GW 123 can also communicate data to other externalnetworks 131A, which can include the Internet, IP multimedia subsystem(IPS) network, and other networks. Generally, the application server 184may be an element offering applications that use IP bearer resourceswith the core network (e.g., UMTS Packet Services (PS) domain, LTE PSdata services, etc.). In this aspect, the P-GW 123 is shown to becommunicatively coupled to an application server 184 via an IP interface125. The application server 184 can also be configured to support one ormore communication services (e.g., Voice-over-Internet Protocol (VoIP)sessions, PTT sessions, group communication sessions, social networkingservices, etc.) for the UEs 101 and 102 via the CN 120.

The P-GW 123 may further be a node for policy enforcement and chargingdata collection. Policy and Charging Rules Function (PCRF) 126 is thepolicy and charging control element of the CN 120. In a non-roamingscenario, in some aspects, there may be a single PCRF in the Home PublicLand Mobile Network (HPLMN) associated with a UE's Internet ProtocolConnectivity Access Network (IP-CAN) session. In a roaming scenario withlocal breakout of traffic, there may be two PCRFs associated with a UE'sIP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF(V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF126 may be communicatively coupled to the application server 184 via theP-GW 123. The application server 184 may signal the PCRF 126 to indicatea new service flow and select the appropriate Quality of Service (QoS)and charging parameters. The PCRF 126 may provision this rule into aPolicy and Charging Enforcement Function (PCEF) (not shown) with theappropriate traffic flow template (TFT) and QoS class of identifier(QCI), which commences the QoS and charging as specified by theapplication server 184.

In an example, any of the nodes 111 or 112 can be configured tocommunicate to the UEs 101, 102 (e.g., dynamically) an antenna panelselection and a receive (Rx) beam selection that can be used by the UEfor data reception on a physical downlink shared channel (PDSCH) as wellas for channel state information reference signal (CSI-RS) measurementsand channel state information (CSI) calculation.

In an example, any of the nodes 111 or 112 can be configured tocommunicate to the UEs 101, 102 (e.g., dynamically) an antenna panelselection and a transmit (Tx) beam selection that can be used by the UEfor data transmission on a physical uplink shared channel (PDSCH) aswell as for sounding reference signal (SRS) transmission.

In some aspects, the communication network 140A can be an IoT network.One of the current enablers of IoT is the narrowband-IoT (NB-IoT).NB-IoT has objectives such as coverage extension, UE complexityreduction, long battery lifetime, and backward compatibility with theLTE network. In addition, NB-IoT aims to offer deployment flexibilityallowing an operator to introduce NB-IoT using a small portion of itsexisting available spectrum, and operate in one of the following threemodalities: (a) standalone deployment (the network operates in re-farmedGSM spectrum); (b) in-band deployment (the network operates within theLTE channel); and (c) guard-band deployment (the network operates in theguard band of legacy LTE channels). In some aspects, such as withfurther enhanced NB-IoT (FeNB-IoT), support for NB-IoT in small cellscan be provided (e.g., in microcell, picocell or femtocell deployments).One of the challenges NB-IoT systems face for small cell support is theUL/DL link imbalance, where for small cells the base stations have lowerpower available compared to macro-cells, and, consequently, the DLcoverage can be affected and/or reduced. In addition, some NB-IoT UEscan be configured to transmit at maximum power if repetitions are usedfor UL transmission. This may result in large inter-cell interference indense small cell deployments.

In some aspects, the UE 101 can receive configuration information 190Avia, e.g., higher layer signaling or other types of signaling. Theconfiguration information 190A can downlink control information (DCI)with information that can be used for configuring PT-RS as disclosedherein below. In response to the configuration information, the UE 101can communicate PT-RS information 192A back to the gNB 111, as describedherein below.

FIG. 1B is a simplified diagram of a next generation (NG) systemarchitecture 140B in accordance with some aspects. Referring to FIG. 1B,the NG system architecture 140B includes RAN 110 and a 5G network core(5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs128 and NG-eNBs 130. The gNBs 128 and the NG-eNBs 130 can becommunicatively coupled to the UE 102 via, e.g., an N1 interface.

The core network 120 (e.g., a 5G core network or 5GC) can include anaccess and mobility management function (AMF) 132 and/or a user planefunction (UPF) 134. The AMF 132 and the UPF 134 can be communicativelycoupled to the gNBs 128 and the NG-eNBs 130 via NG interfaces. Morespecifically, in some aspects, the gNBs 128 and the NG-eNBs 130 can beconnected to the AMF 132 by NG-C interfaces, and to the UPF 134 by NG-Uinterfaces. The gNBs 128 and the NG-eNBs 130 can be coupled to eachother via. Xn interfaces.

In some aspects, a gNB 128 can include a node providing new radio (NR)user plane and control plane protocol termination towards the UE, and isconnected via the NG interface to the 5GC 120. In some aspects, anNG-eNB 130 can include a node providing evolved universal terrestrialradio access (E-UTRA) user plane and control plane protocol terminationstowards the UE, and is connected via the NG interface to the 5GC 120.

In some aspects, each of the gNBs 128 and the NG-eNBs 130 can beimplemented as a base station, a mobile edge server, a small cell, ahome eNB, and so forth.

FIG. 1C illustrates an example MulteFire Neutral Host Network (NHN) 5Garchitecture 140C in accordance with some aspects. Referring to FIG. 1C,the MulteFire 5G architecture 140C can include the UE 102, NG-RAN 110,and core network 120. The NG-RAN 110 can be a MuIteFire NG-RAN (MFNG-RAN), and the core network 120 can be a MulteFire 5G neutral hostnetwork (NHN).

In some aspects, the MF NHN 120 can include a neutral host AMF (NH AMF)132, a NFI SMF 136, a NFI UPF 134, and a local AAA proxy 151C. The AAAproxy 151C can provide connection to a 3GPP AAA server 155C and aparticipating service provider AAA (PSP AAA) server 153C. The NH-UPF 134can provide a connection to a data network 157C.

The MF NG-RAN 120 can provide similar functionalities as an NG-RANoperating under a 3GPP specification. The NH-AMF 132 can be configuredto provide similar functionality as a AMF in a 3GPP 5G core network(e.g., as described in reference to FIG. 1D). The NH-SMF 136 can beconfigured to provide similar functionality as a SMF in a 3GPP 5G corenetwork (e.g., as described in reference to FIG. 1D). The NH-UPF 134 canbe configured to provide similar functionality as a UPF in a 3GPP 5Gcore network (e.g., as described in reference to FIG. 1D).

FIG. 1D illustrates a functional split between NG-RAN and the 5G Core(5GC) in accordance with some aspects. Referring to FIG. 1D, there isillustrated a more detailed diagram of the functionalities that can beperformed by the gNBs 128 and the NG-eNBs 130 within the NG-RAN 110, aswell as the AMF 132, the UPF 134, and the SMF 136 within the 5GC 120. Insome aspects, the 5GC 120 can provide access to the Internet 138 to oneor more devices via the NG-RAN 110.

In some aspects, the gNBs 128 and the NG-eNBs 130 can be configured tohost the following functions: functions for Radio Resource Management(e.g., inter-cell radio resource management 129A, radio bearer control129B, connection mobility control 129C, radio admission control 129D,dynamic allocation of resources to UEs in both uplink and downlink(scheduling) 129F); IP header compression, encryption and integrityprotection of data; selection of an AMF at UE attachment when no routingto an AMF can be determined from the information provided by the UE;routing of User Plane data towards UPF(s); routing of Control Planeinformation towards AMF; connection setup and release; scheduling andtransmission of paging messages (originated from the AMF); schedulingand transmission of system broadcast information (originated from theAMF or Operation and Maintenance); measurement and measurement reportingconfiguration for mobility and scheduling 129E; transport level packetmarking in the uplink; session management; support of network slicing;QoS flow management and mapping to data radio bearers; support of UEs inRRC_INACTIVE state; distribution function for non-access stratum (NAS)messages; radio access network sharing; dual connectivity; and tightinterworking between NR and E-UTRA, to name a few.

In some aspects, the AMF 132 can be configured to host the followingfunctions, for example: NAS signaling termination; NAS signalingsecurity 133A; access stratum (AS) security control; inter core network(CN) node signaling for mobility between 3GPP access networks; idlestate/mode mobility handling 133B, including mobile device, such as a UEreachability (e.g., control and execution of paging retransmission);registration area management; support of intra-system and inter-systemmobility; access authentication; access authorization including check ofroaming rights; mobility management control (subscription and policies);support of network slicing; and/or SMF selection, among other functions.

The UPF 134 can be configured to host the following functions, forexample: mobility anchoring 135A (e.g., anchor point forIntra-/Inter-RAT mobility); packet data unit (PDU) handling 135B (e.g.,external PDU session point of interconnect to data network); packetrouting and forwarding; packet inspection and user plane part of policyrule enforcement; traffic usage reporting; uplink classifier to supportrouting traffic flows to a data network; branching point to supportmulti-homed PDU session; QoS handling for user plane, e.g., packetfiltering, gating, UL/DL rate enforcement; uplink traffic verification(SDF to QoS flow mapping); and/or downlink packet buffering and downlinkdata notification triggering, among other functions.

The Session Management function (SMF) 136 can be configured. to host thefollowing functions, for example: session management; UE addressallocation and management 137A; selection and control of user planefunction (UPF); PDU session control 13M, including configuring trafficsteering at UPF 134 to route traffic to proper destination; control partof policy enforcement and QoS; and/or downlink data notification, amongother functions.

FIG. 1E and FIG. 1F illustrate a non-roaming 5G system architecture inaccordance with some aspects. Referring to FIG. 1E, there is illustrateda 5G system architecture 140E in a reference point representation. Morespecifically, UE 102 can be in communication with RAN 110 as well as oneor more other 5G core (5GC) network entities. The 5G system architecture140E includes a plurality of network functions (NFs), such as access andmobility management function (AMF) 132, session management function(SMF) 136, policy control function (PCF) 148, application function (AF)150, user plane function (UPF) 134, network slice selection function(NSSF) 142, authentication server function (AUSF) 144, and unified datamanagement (UDM)/home subscriber server (HSS) 146. The UPF 134 canprovide a connection to a data network (DN) 152, which can include, forexample, operator services, Internet access, or third-party services.The AMF can be used to manage access control and mobility, and can alsoinclude network slice selection functionality. The SMF can be configuredto set up and manage various sessions according to a network policy. TheUPF can be deployed in one or more configurations according to a desiredservice type. The PCF can be configured to provide a policy frameworkusing network slicing, mobility management, and roaming (similar to PCRFin a 4G communication system). The UDM can be configured to storesubscriber profiles and data (similar to an HSS in a 4G communicationsystem).

In some aspects, the 5G system architecture 140E includes an IPmultimedia subsystem (IMS) 168E as well as a plurality of IP multimediacore network subsystem entities, such as call session control functions(CSCFs). More specifically, the IMS 168E includes a CSCF, which can actas a proxy CSCF (P-CSCF) 162E, a serving CSCF (S-CSCF) 164E, anemergency CSCF (E-CSCF) (not illustrated in FIG. 1E), and/orinterrogating CSCF (I-CSCF) 166E. The P-CSCF 162E can be configured tobe the first contact point for the UE 102 within the IM subsystem (IMS)168E. The S-CSCF 164E can be configured to handle the session states inthe network, and the E-CSCF can be configured to handle certain aspectsof emergency sessions such as routing an emergency request to thecorrect emergency center or PSAP. The I-CSCF 166E can be configured tofunction as the contact point within an operator's network for all IMSconnections destined to a subscriber of that network operator, or aroaming subscriber currently located within that network operator'sservice area. In some aspects, the I-CSCF 166E can be connected toanother IP multimedia network 170E, e.g. an IMS operated by a differentnetwork operator.

In some aspects, the UDM HSS 146 can be coupled to an application server160E, which can include a telephony application server (TAS) or anotherapplication server (AS). The AS 160E can be coupled to the IMS 168E viathe S-CSCF 164E and/or the I-CSCF 166E.

In some aspects, the 5G system architecture 140E can use a unifiedaccess barring mechanism using one or more of the techniques describedherein, which access barring mechanism can be applicable for all RRCstates of the UE 102, such as RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVEstates.

In some aspects, the 5G system architecture 140E can be configured touse 5G access control mechanism techniques described herein, based onaccess categories that can be categorized by a minimum default set ofaccess categories, which are common across all networks. Thisfunctionality can allow the public land mobile network PLMN, such as avisited PLMN (VPLMN) to protect the network against different types ofregistration attempts, enable acceptable service for the roamingsubscriber and enable the VPLMN to control access attempts aiming atreceiving certain basic services. It also provides more options andflexibility to individual operators by providing a set of accesscategories, which can be configured and used in operator specific ways.

Referring to FIG. 1F, there is illustrated a 5G system architecture 140Fand a service-based representation. System architecture 140F can besubstantially similar to (or the same as) system architecture 140E. Inaddition to the network entities illustrated in FIG. 1E, systemarchitecture 140F can also include a network exposure function (NEF) 154and a network repository function (NRF) 156.

In some aspects, 5G system architectures can be service-based andinteraction between network functions can be represented bycorresponding point-to-point reference points Ni (as illustrated in FIG.1E) or as service-based interfaces (as illustrated in FIG. 1F).

A reference point representation shows that an interaction can existbetween corresponding NF services. For example, FIG. 1E illustrates thefollowing reference points: N1 (between the UE 102 and the AMF 132), N2(between the RAN 110 and the AMF 132), N3 (between the RAN 110 and theUPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF148 and the AF 150), N6 (between the UPF 134 and the DN 152), N7(between the SMF 136 and the PCF 148), N8 (between the UDM 146 and theAMF 132), N9 (between two UPFs 134), N10 (between the UDN4 146 and theSMF 136), N11 (between the AMF 132 and the SMF 136), N12 (between theAUSF 144 and the AN/IF 132), N13 (between the AUSF 144 and the UDM 146),N14 (between two AMFs 132), N15 (between the PCF 148 and the AMF 132 incase of a non-roaming scenario, or between the PCF 148 and a visitednetwork and AMF 132 in case of a roaming scenario), N16 (between twoSMFs; not illustrated in FIG. 1E), and N22 (between AMF 132 and NSSF142). Other reference point representations not shown in FIG. 1E canalso be used.

In some aspects, as illustrated in FIG. 1F, service-basedrepresentations can be used to represent network functions within thecontrol plane that enable other authorized network functions to accesstheir services. In this regard, 5G system architecture 140F can includethe following service-based interfaces: Namf 158H (a service-basedinterface exhibited by the AMF 132), Nsmf 158I (a service-basedinterface exhibited by the SMF 136), Nnef 158B (a service-basedinterface exhibited by the NEF 154), Npcf 158D (a service-basedinterface exhibited by the PCF 148), a Nudm 158E (a service-basedinterface exhibited by the UDM 146), Naf 158F (a service-based interfaceexhibited by the AF 150), Nnrf 158C (a service-based interface exhibitedby the NRF 156), Nnssf 158A (a service-based interface exhibited by theNSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF144). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf)not shown in FIG. 1F can also be used.

FIG. 1G illustrates an example CIoT network architecture in accordancewith some aspects. Referring to FIG. 1G, the CIoT architecture 140G caninclude the UE 102 and the RAN 110 coupled to a plurality of corenetwork entities. In some aspects, the UE 102 can be machine-typecommunication (MTC) UE. The CIoT network architecture 140G can furtherinclude a mobile services switching center (MSC) 160, MME 121, a servingGPRS support note (SGSN) 162, a S-GW 122, an IP-Short-Message-Gateway(IP-SM-GW) 164, a Short Message Service Service Center (SMS-SC)/gatewaymobile service center (GMSC)/Interworking MSC (IWMSC) 166, CIoTCinterworking function (MTC-IWF) 170, a Service Capability ExposureFunction (SCEF) 172, a gateway GPRS support node (GGSN)/Packet-GW (P-GW)174, a charging data function (CDF)/charging gateway function (CGF) 176,a home subscriber server (HSS)/a home location register (HLR) 177, shortmessage entities (SME) 168, CIoTC authorization, authentication, andaccounting (MTC AAA) server 178, a service capability server (SCS) 180,and application servers (AS) 182 and 184.

In some aspects, the SCEF 172 can be configured to securely exposeservices and capabilities provided by various 3GPP network interfaces.The SCEF 172 can also provide means for the discovery of the exposedservices and capabilities, as well as access to network capabilitiesthrough various network application programming interfaces (es., APIinterfaces to the SCS 180).

FIG. 1G further illustrates various reference points between differentservers, functions, or communication nodes of the CIoT networkarchitecture 140G. Some example reference points related to CIoTC-IWF170 and SCEF 172 include the following: Tsms (a reference point used byan entity outside the 3GPP network to communicate with UEs used forCIoTC via SMS), Tsp (a reference point used by a SCS to communicate withthe CIoTC-IWF related control plane signaling), T4 (a reference pointused between CIoTC-IWF 170 and the SMS-SC 166 in the HPLMN), T6 a (areference point used between SCEF 172 and serving MME 121), T6 b (areference point used between SCEF 172 and serving SGSN 162), T8 (areference point used between the SCEF 172 and the SCS/AS 180/182), S6 m(a reference point used by CIoTC-IWF 170 to interrogate HSS/HLR 177), S6n (a reference point used by CIoTC-AAA server 178 to interrogate HSS/HLR177), and S6 t (a reference point used between SCEF 172 and HSS/HLR177).

In some aspects, the CIoT UE 102 can be configured to communicate withone or more entities within the CIoT architecture 140G via the RAN 110according to a Non-Access Stratum (NAS) protocol, and using one or morereference points, such as a narrowband air interface, for example, basedon one or more communication technologies, such as OrthogonalFrequency-Division Multiplexing (OFDM) technology. As used herein, theterm “CIoT UE” refers to a UE capable of CIoT optimizations, as part ofa CIoT communications architecture.

In some aspects, the NAS protocol can support a set of NAS messages forcommunication between the CIoT UE 102 and an Evolved Packet System (EPS)Mobile Management Entity (MME) 121 and SGSN 162.

In some aspects, the CIoT network architecture 140F can include a packetdata network, an operator network, or a cloud service network, having,for example, among other things, a Service Capability Server (SCS) 180,an Application Server (AS) 182, or one or more other external servers ornetwork components.

The RAN 110 can be coupled to the HSS/HLR servers 177 and the AAAservers 178 using one or more reference points including, for example,an air interface based on an Sha reference point, and configured toauthenticate/authorize CIoT UE 102 to access the CIoT network. The RAN110 can be coupled to the CIoT network architecture 140G using one ormore other reference points including, for example, an air interfacecorresponding to an SGi/Gi interface for 3GPP accesses. The RAN 110 canbe coupled to the SCEF 172 using, for example, an air interface based ona T6 a/T6 b reference point, for service capability exposure. In someaspects, the SCEF 172 may act as an API GW towards a third-partyapplication server such as AS 182. The SCEF 172 can be coupled to theHSS/HLR 177 and CIoTC AAA 178 servers using an S6 t reference point, andcan further expose an Application Programming Interface to networkcapabilities.

In certain examples, one or more of the CIoT devices disclosed herein,such as the CIoT UE 102, the CIoT RAN 110, etc., can include one or moreother non-CIoT devices, or non-CIoT devices acting as CIoT devices, orhaving functions of a CIoT device. For example, the CIot UE 102 caninclude a smart phone, a tablet computer, or one or more otherelectronic device acting as a CIoT device for a specific function, whilehaving other additional functionality.

In some aspects, the RAN 110 can include a CIoT enhanced. Node B (CIoTeNB) 111 communicatively coupled to the CIoT Access Network Gateway(CIoT GW) 195. In certain examples, the RAN 110 can include multiplebase stations (e.g., CIoT eNBs) connected to the CIoT GW 195, which caninclude MSC 160, MIME 121, SGSN 162, and/or S-GW 122. In certainexamples, the internal architecture of RAN 110 and CIoT GW 195 may beleft to the implementation and need not be standardized.

As used herein, the term “circuitry” may refer to, be part of, orinclude an Application Specific integrated Circuit (ASIC) or otherspecial purpose circuit, an electronic circuit, a processor (shared,dedicated, or group), or memory (shared, dedicated, or group) executingone or more software or firmware programs, a combinational logiccircuit, or other suitable hardware components that provide thedescribed functionality. In some aspects, the circuitry may beimplemented in, or functions associated with the circuitry may beimplemented by, one or more software or him ware modules. In someaspects, circuitry may include logic, at least partially operable inhardware. In some aspects, circuitry as well as modules disclosed hereinmay be implemented in combinations of hardware, software and/orfirmware. In some aspects, functionality associated with a circuitry canbe distributed across more than one piece of hardware orsoftware/firmware module. In some aspects, modules (as disclosed herein)may include logic, at least partially operable in hardware. Aspectsdescribed herein may be implemented into a system using any suitablyconfigured hardware or software.

FIG. 1H illustrates an example Service Capability Exposure Function(SCEF) in accordance with some aspects. Referring to FIG. 1H, the SCEF172 can be configured to expose services and capabilities provided by3GPP network interfaces to external third party service provider servershosting various applications. In some aspects, a 3GPP network such asthe CIoT architecture 140G, can expose the following services andcapabilities: a home subscriber server (HSS) 116H, a policy and chargingrules function (PCRF) 118H, a packet flow description function (PFDF)120H, a 11/1ME/SGSN 122H, a broadcast multicast service center (BM-SC)124H, a serving call server control function (S-CSCF) 126H, a RANcongestion awareness function (RCAF) 128H, and one or more other networkentities 130H. The above-mentioned services and capabilities of a 3GPPnetwork can communicate with the SCEF 172 via one or more interfaces asillustrated in FIG. 1H.

The SCEF 172 can be configured to expose the 3GPP network services andcapabilities to one or more applications running on one or more servicecapability server (SCS)/application server (AS), such as SCS/AS 102H,104H, . . . , 106H. Each of the SCS/AG 102H-106H can communicate withthe SCEF 172 via application programming interfaces (APIs) 108H, 110H,112H, . . . , 114H, as seen in FIG. 1H.

FIG. 1I illustrates an example roaming architecture for SCEF inaccordance with some aspects. Referring to FIG. 1I, the SCEF 172 can belocated in HPLMN 110I and can be configured to expose 3GPP networkservices and capabilities, such as 102I, . . . , 104I. In some aspects,3GPP network services and capabilities, such as 106I, . . . , 108I, canbe located within VPLMN 112I. In this case, the 3GPP network servicesand capabilities within the VPLMN 112I can be exposed to the SCEF 172via an interworking SCEF (MK-SCEF) 197 within the VPLMN 112I.

FIG. 1J illustrates an example Evolved Universal Terrestrial RadioAccess (E-UTRA) New Radio Dual Connectivity (EN-DC) architecture inaccordance with some aspects. Referring to FIG. 1G, the EN-DCarchitecture 140J includes radio access network (or E-TRA network, orE-TRAN) 110 and EPC 120. The EPC 120 can include MIMEs 121 and S-GWs122. The E-UTRAN 110 can include nodes 111 (e.g., eNBs) as well asEvolved Universal Terrestrial Radio Access New Radio (EN) nextgeneration evolved Node-Bs (en-gNBs) 128.

In some aspects, en-gNBs 128 can be configured to provide NR user planeand control plane protocol terminations towards the UE 102, and actingas Secondary Nodes (or SgNBs) in the EN-DC communication architecture140J. The eNBs 111 can be configured as master nodes (or MeNBs) in theEN-DC communication architecture 140J, as illustrated in FIG. 1J, theeNBs 111 are connected to the EPC 120 via the S1 interface and to theEN-gNBs 128 via the X2 interface. The EN-gNBs 128 may be connected tothe EPC 120 via the S1-U interface, and to other EN-gNBs via the X2-Uinterface.

FIG. 2 illustrates example components of a device 200 in accordance withsome aspects. In some aspects, the device 200 may include applicationcircuitry 202, baseband circuitry 204, Radio Frequency (RF) circuitry206, front-end module (FEM) circuitry 208, one or more antennas 210, andpower management circuitry (PMC) 212 coupled together at least as shown.The components of the illustrated device 200 may be included in a UE ora RAN node. In some aspects, the device 200 may include fewer elements(e.g., a RAN node may not utilize application circuitry 202, and insteadinclude a processor/controller to process IP data received from an EPC).In some aspects, the device 200 may include additional elements such as,for example, memory/storage, display, camera, sensor, and/orinput/output (I/O) interface elements. In other aspects, the componentsdescribed below may be included in more than one device (e.g., saidcircuitries may be separately included in more than one device forCloud-RAN (C-RAN) implementations).

The application circuitry 202 may include one or more applicationprocessors. For example, the application circuitry 202 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors, special-purpose processors, and dedicatedprocessors (es., graphics processors, application processors, etc.). Theprocessors may be coupled with, and/or may include, memory/storage andmay be configured to execute instructions stored in the memory/storageto enable various applications or operating systems to run on the device200. In some aspects, processors of application circuitry 202 mayprocess IP data packets received from an EPC.

The baseband circuitry 204 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry 204 may include one or more baseband processors orcontrol logic to process baseband signals received from a receive signalpath of the RF circuitry 206 and to generate baseband signals for atransmit signal path of the RF circuitry 206. Baseband processingcircuity 204 may interface with the application circuitry 202 forgeneration and processing of the baseband signals and for controllingoperations of the RF circuitry 206. For example, in some aspects, thebaseband circuitry 204 may include a third generation (3G) basebandprocessor 204A, a fourth generation (4G) baseband processor 204B, afifth generation (5G) baseband processor 204C, or other basebandprocessor(s) 204D for other existing generations, generations indevelopment or to be developed in the future (e.g., second generation(2G), sixth generation (6G), etc.). The baseband circuitry 204 (e.g.,one or more of baseband processors 204A-D) may handle various radiocontrol functions that enable communication with one or more radionetworks via the RF circuitry 206. In other aspects, some or all of thefunctionality of baseband processors 204A-D may be included in modulesstored in the memory 204G and executed via a Central Processing Unit(CPU) 204E. The radio control functions may include, but are not limitedto, signal modulation/demodulation, encoding/decoding, radio frequencyshifting, etc. In some aspects, modulation/demodulation circuitry of thebaseband circuitry 204 may include Fast-Fourier Transform (FFT),precoding, or constellation mapping/de-mapping functionality. In someaspects, encoding/decoding circuitry of the baseband circuitry 204 mayinclude convolution, tail-biting convolution, turbo, Viterbi, orLow-Density Parity Check (LDPC) encoder/decoder functionality. Aspectsof modulation/demodulation and encoder/decoder functionality are notlimited to these examples and may include other suitable functionalityin other aspects.

In some aspects, the baseband circuitry 204 may include one or moreaudio digital signal processor(s) (DSP) 204F. The audio DSP(s) 204F maybe include elements for compression/decompression and echo cancellationand may include other suitable processing elements in other aspects.Components of the baseband circuitry 204 may be suitably combined in asingle chip, a single chipset, or disposed on a same circuit board insome aspects. In some aspects, some or all of the constituent componentsof the baseband circuitry 204 and the application circuitry 202 may beimplemented together such as, for example, on a system on a chip (SOC).

In some aspects, the baseband circuitry 204 may provide forcommunication compatible with one or more radio technologies. Forexample, in some aspects, the baseband circuitry 204 may supportcommunication with an evolved universal terrestrial radio access network(EUTRAN) or other wireless metropolitan area networks (WMAN), a wirelesslocal area network (WLAN), and/or a wireless personal area network(WPAN). Baseband circuitry 204 configured to support radiocommunications of more than one wireless protocol may be referred to asmulti-mode baseband circuitry, in some aspects.

RF circuitry 206 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious aspects, the RF circuitry 206 may include switches, filters,amplifiers, etc. to facilitate the communication with the wirelessnetwork. RF circuitry 206 may include a receive signal path which mayinclude circuitry to down-convert RF signals received from the FEMcircuitry 208 and provide baseband signals to the baseband circuitry204. RF circuitry 206 may also include a transmit signal path which mayinclude circuitry to up-convert baseband signals provided by thebaseband circuitry 204 and provide RF output signals to the FEMcircuitry 208 for transmission.

In some aspects, the receive signal path of the RF circuitry 206 mayinclude a mixer 206A, an amplifier 206B, and a filter 206C. In someaspects, the transmit signal path of the RF circuitry 206 may include afilter 206C and a mixer 206A. RF circuitry 206 may also include asynthesizer 206D for synthesizing a frequency for use by the mixer 206Aof the receive signal path and the transmit signal path. In someaspects, the mixer 206A of the receive signal path may be configured todown-convert RF signals received from the FEM circuitry 208 based on thesynthesized frequency provided by synthesizer 206D. The amplifier 206Bmay be configured to amplify the down-converted signals and the filter206C may be a low-pass filter (LPF) or band-pass filter (BPF) configuredto remove unwanted signals from the down-converted signals to generateoutput baseband signals. Output baseband signals may be provided to thebaseband circuitry 204 for further processing. In some aspects, theoutput baseband signals may optionally be zero-frequency basebandsignals. In some aspects, mixer 206A of the receive signal path maycomprise passive mixers.

In some aspects, the mixer 206A of the transmit signal path may beconfigured to up-convert input baseband signals based on the synthesizedfrequency provided by the synthesizer 206D to generate RF output signalsfor the FEM circuitry 208. The baseband signals may be provided by thebaseband circuitry 204 and may be filtered by filter 206C.

In some aspects, the mixer 206A of the receive signal path and the mixer206A of the transmit signal path may include two or more mixers and maybe arranged for quadrature down conversion and up conversion,respectively. In some aspects, the mixer 206A of the receive signal pathand the mixer 206A of the transmit signal path may include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some aspects, the mixer 206A of the receive signal pathand the mixer 206A may be arranged for direct down conversion and directup conversion, respectively. In some aspects, the mixer 206A of thereceive signal path and the mixer 206A of the transmit signal path maybe configured for super-heterodyne operation.

In some aspects, the output baseband signals and the input basebandsignals may optionally be analog baseband signals. According to somealternate aspects, the output baseband signals and the input basebandsignals may be digital baseband signals. in these alternate aspects, theRF circuitry 206 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry204 may include a digital baseband interface to communicate with the RFcircuitry 206.

In some dual-mode aspects, a separate radio IC circuitry may optionallybe provided for processing signals for each spectrum.

In some aspects, the synthesizer 206D may optionally be a fractional-Nsynthesizer or a fractional N/N+1 synthesizer, although other types offrequency synthesizers may be suitable. For example, the synthesizer206D may be a delta-sigma synthesizer, a frequency multiplier, or asynthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer 206D may be configured to synthesize an output frequencyfor use by the mixer 206A of the RF circuitry 206 based on a frequencyinput and a divider control input. In some aspects, the synthesizer 206Dmay be a fractional N/N+1 synthesizer.

In some aspects, frequency input may be provided by a voltage controlledoscillator (VCO), although that is not a requirement. Divider controlinput may be provided, for example, by either the baseband circuitry 204or the applications circuitry 202 depending on the desired outputfrequency. In some aspects, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplications circuitry 202.

Synthesizer circuitry 206D of the RF circuitry 206 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some aspects, the divider may be a dual modulus divider(DMD) and the phase accumulator may be a digital phase accumulator(DPA). In some aspects, the DMD may be configured to divide the inputsignal by either N or N+1 (e.g., based on a carry out) to provide afractional division ratio. In some example aspects, the DLL, may includea set of cascaded, tunable, delay elements, a phase detector, a chargepump and a D-type flip-flop. In these aspects, the delay elements may beconfigured to break a VCO period up into Nd equal packets of phase,where Nd is the number of delay elements in the delay line. In this way,the DLL provides negative feedback to assist in keeping the total delaythrough the delay line to one VCO cycle.

In some aspects, synthesizer circuitry 206D may be configured togenerate a carrier frequency as the output frequency, while in otheraspects, the output frequency may be a multiple of the carrier frequency(e.g., twice the carrier frequency, or four times the carrier frequency)and may be used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In some aspects,the output frequency may be a LO frequency (fLO). In some aspects, theRF circuitry 206 may include an IQ/polar converter.

FEM circuitry 208 may include a receive signal path which may includecircuitry configured to operate on RF signals received from one or moreantennas 210, and/or to amplify the received signals and provide theamplified versions of the received signals to the RF circuitry 206 forfurther processing. FEM circuitry 208 may also include a transmit signalpath which may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 206 for transmission by one ormore of the one or more antennas 210. In various aspects, theamplification through the transmit signal paths or the receive signalpaths may be done in part or solely in the RF circuitry 206, in part orsolely in the FEM circuitry 208, or in both the RF circuitry 206 and theFEM circuitry 208.

In some aspects, the FEM circuitry 208 may include a TX/RX switch toswitch between transmit mode and receive mode operation. The FEMcircuitry 208 may include a receive signal path and a transmit signalpath. The receive signal path of the FEM circuitry 208 may include anLNA to amplify received RF signals and provide the amplified received RFsignals as an output (e.g., to the RF circuitry 206). The transmitsignal path of the FEM circuitry 208 may include a power amplifier (PA)to amplify input RF signals (e.g., provided by RF circuitry 206), andone or more filters to generate RF signals for subsequent transmission(e.g., by one or more of the one or more antennas 210).

In some aspects, the PMC 212 may manage power provided to the basebandcircuitry 204. The PMC 212 may control power-source selection, voltagescaling, battery charging, and/or DC-to-DC conversion. The PMC 212 may,in some aspects, be included when the device 200 is capable of beingpowered by a battery, for example, when the device is included in a UE.The PMC 212 may increase the power conversion efficiency while providingbeneficial implementation size and heat dissipation characteristics.

FIG. 2 shows the PMC 212 coupled with the baseband circuitry 204. Inother aspects, the PMC 212 may be additionally or alternatively coupledwith, and perform similar power management operations for, othercomponents such as, but not limited to, application circuitry 202, RFcircuitry 206, or FEM circuitry 208.

In some aspects, the PMC 212 may control, or otherwise be part of,various power saving mechanisms of the device 200. For example, if thedevice 200 is in an RRC_Connected state, in which it is still connectedto the RAN node as it expects to receive traffic shortly, then it mayenter a state known as Discontinuous Reception Mode (DRX) after a periodof inactivity. During this state, the device 200 may power down forbrief intervals of time and thus save power.

According to some aspects, if there is no data traffic activity for anextended period of time, then the device 200 may transition off to anRRC_Idle state, in which it disconnects from the network and does notperform operations such as channel quality feedback, handover, etc. Thedevice 200 goes into a very low power state and it performs pagingduring which it periodically wakes up to listen to the network and thenpowers down again. The device 200 may transition back to RRC_Connectedstate to receive data.

An additional power saving mode may allow a device to be unavailable tothe network for periods longer than a paging interval (ranging fromseconds to a few hours). During this time, the device 200 in someaspects may be unreachable to the network and may power down. Any datasent during this time incurs a delay, which may be large, and it isassumed the delay is acceptable.

Processors of the application circuitry 202 and processors of thebaseband circuitry 204 may be used to execute elements of one or moreinstances of a protocol stack. For example, processors of the basebandcircuitry 204, alone or in combination, may be used execute Layer 3,Layer 2, or Layer 1 functionality, while processors of the applicationcircuitry 202 may utilize data (e.g., packet data) received from theselayers and further execute Layer 4 functionality (e.g., transmissioncommunication protocol (TCP) and user datagram protocol (UDP) layers).As referred to herein, Layer 3 may comprise a radio resource control(RRC) layer, described in further detail below. As referred to herein,Layer 2 may comprise a medium access control (MAC) layer, a radio linkcontrol (RLC) layer, and a packet data convergence protocol (PDCP)layer, described in further detail below. As referred to herein, Layer 1may comprise a physical (PHY) layer of a UE/RAN node, described infurther detail below.

FIG. 3 illustrates example interfaces of baseband circuitry 204, inaccordance with some aspects. As discussed above, the baseband circuitry204 of FIG. 2 may comprise processors 204A-204E and a memory 204Gutilized by said processors. Each of the processors 204A-204E mayinclude a memory interface, 304A-304E, respectively, to send/receivedata to/from the memory 204G.

The baseband circuitry 204 may further include one or more interfaces tocommunicatively couple to other circuities/devices, such as a memoryinterface 312 (e.g., an interface to send/receive data to/from memoryexternal to the baseband circuitry 204), an application circuitryinterface 314 (e.g., an interface to send/receive data to/from theapplication circuitry 202 of FIG. 2 ), an RF circuitry interface 316(e.g., an interface to send/receive data to/from RF circuitry 206 ofFIG. 2 ), a wireless hardware connectivity interface 318 (e.g., aninterface to send/receive data to/from Near Field Communication (NFC)components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi®components, and other communication components), and a power managementinterface 320 (e.g., an interface to send/receive power or controlsignals to/from the PMC 212).

FIG. 4 is an illustration of a control plane protocol stack inaccordance with some aspects. In one aspect, a control plane 400 isshown as a communications protocol stack between the UE 102, the RANnode 128 (or alternatively, the RAN node 130), and the AMF 132.

The PHY layer 401 may in some aspects transmit or receive informationused by the MAC layer 402 over one or more air interfaces. The PHY layer401 may further perform link adaptation or adaptive modulation andcoding (AMC), power control, cell search (e.g., for initialsynchronization and handover purposes), and other measurements used byhigher layers, such as the RRC layer 405. The PHY layer 401 may in someaspects still further perform error detection on the transport channels,forward error correction (FEC) coding/decoding of the transportchannels, modulation/demodulation of physical channels, interleaving,rate matching, mapping onto physical channels, and Multiple InputMultiple Output (MIMO) antenna processing.

The MAC layer 402 may in some aspects perform mapping between logicalchannels and transport channels, multiplexing of MAC service data units(SDUs) from one or more logical channels onto transport blocks (TB) tobe delivered to PHY via transport channels, de-multiplexing MAC SDUs toone or more logical channels from transport blocks (TB) delivered fromthe PHY via transport channels, multiplexing MAC SDUs onto TBs,scheduling information reporting, error correction through hybridautomatic repeat request (HARQ), and logical channel prioritization.

The RLC layer 403 may in some aspects operate in a plurality of modes ofoperation, including: Transparent Mode (TM), Unacknowledged Mode (UM),and Acknowledged Mode (AM). The RLC layer 403 may execute transfer ofupper layer protocol data units (PDUs), error correction throughautomatic repeat request (ARQ) for AM data transfers, and segmentationand reassembly of RLC SDUs for UM and AM data transfers. The RLC layer403 may also maintain sequence numbers independent of the ones in PDCPfor UM and AM data transfers. The RLC layer 403 may also in some aspectsexecute re-segmentation of RLC data PDUs for AM data transfers, detectduplicate data for AM data transfers, discard RLC SDUs for UM and AMdata transfers, detect protocol errors for AM data transfers, andperform RLC re-establishment.

The PDCP layer 404 may in some aspects execute header compression anddecompression of IP data, maintain PDCP Sequence Numbers (SNs), performin-sequence delivery of upper layer PDUs at re-establishment of lowerlayers, perform reordering and eliminate duplicates of lower layer SDUs,execute PDCP PDU routing for the case of split bearers, executeretransmission of lower layer SDUs, cipher and decipher control planeand user plane data, perform integrity protection and integrityverification of control plane and user plane data, control timer-baseddiscard of data, and perform security operations (e.g., ciphering,deciphering, integrity protection, integrity verification, etc.).

In some aspects, primary services and functions of the RRC layer 405 mayinclude broadcast of system infounation (e.g., included in Masterinformation Blocks (MlBs) or System information Blocks (SIBs) related tothe non-access stratum (NAS)); broadcast of system information relatedto the access stratum (AS); paging initiated by 5GC 120 or NG-RAN 110,establishment, maintenance, and release of an RRC connection between theLIE and NG-RAN (e.g., RRC connection paging, RRC connectionestablishment, RRC connection addition, RRC connection modification, andRRC connection release, also for carrier aggregation and. DualConnectivity in NR or between E-UTRA and NR); establishment,configuration, maintenance, and release of Signalling Radio Bearers(SRBs) and Data Radio Bearers (DRBs); security functions including keymanagement, mobility functions including handover and context transfer,UE cell selection and reselection and control of cell selection andreselection, and inter-radio access technology (RAT) mobility; andmeasurement configuration for UE measurement reporting. Said MIBs andSIBs may comprise one or more information elements (IEs), which may eachcomprise individual data fields or data structures. The RRC layer 405may also, in some aspects, execute QoS management functions, detectionof and recovery from radio link failure, and NAS message transferbetween the NAS layer 406 in the UE and the NAS layer 406 in the AMF132.

In some aspects, the following NAS messages can be communicated duringthe corresponding NAS procedure, as illustrated in Table 1 below:

TABLE 1 5G NAS 5G NAS 4G NAS 4G NAS Message Procedure Message nameProcedure Registration Initial Attach Request Attach Requestregistration procedure procedure Registration Mobility Tracking AreaTracking area Request registration Update (TAU) updating update Requestprocedure procedure Registration Periodic TAU Request Periodic Requestregistration tracking area update updating procedure procedureDeregistration Deregistration Detach Detach Request procedure Requestprocedure Service Service request Service Service request Requestprocedure Request or procedure Extended Service Request PDU Session PDUsession PDN PDN Establishment establishment Connectivity connectivityRequest procedure Request procedure

In some aspects, when the same message is used for more than oneprocedure, then a parameter can be used (e.g., registration type or TAUtype) which indicates the specific purpose of the procedure, e.g.registration type=“initial registration”, “mobility registration update”or “periodic registration update”.

The UE 101 and the RAN node 128/130 may utilize an NG radio interface(e.g., an LTE-Uu interface or an NR radio interface) to exchange controlplane data via a protocol stack comprising the PHY layer 401, the MAClayer 402, the RLC layer 403, the PDCP layer 404, and the RRC layer 405.

The non-access stratum (NAS) protocol layers 406 form the higheststratum of the control plane between the UE 101 and the AMF 132 asillustrated in FIG. 4 . In aspects, the NAS protocol layers 406 supportthe mobility of the UE 101 and the session management procedures toestablish and maintain IP connectivity between the UE 101 and the UPF134. In some aspects, the UE protocol stack can include one or moreupper layers, above the NAS layer 406. For example, the upper layers caninclude an operating system layer 424, a connection manager 420, andapplication layer 422. In some aspects, the application layer 422 caninclude one or more clients which can be used to perform variousapplication functionalities, including providing an interface for andcommunicating with one or more outside networks. In some aspects, theapplication layer 422 can include an IP multimedia subsystem (IMS)client 426.

The NG Application Protocol (NG-AP) layer 415 may support the functionsof the N2 and N3 interface and comprise Elementary Procedures (EPs). AnEP is a unit of interaction between the RAN node 128/130 and the 5GC120. In certain aspects, the NG-AP layer 415 services may comprise twogroups: UE-associated services and non-UE-associated services. Theseservices perform functions including, but not limited to: UE contextmanagement, PDU session management and management of correspondingNG-RAN resources (e.g. Data Radio Bearers [DRBs]), UE capabilityindication, mobility, NAS signaling transport, and configurationtransfer (es. for the transfer of SON information).

The Stream Control Transmission Protocol (SCTP) layer (which mayalternatively be referred to as the SCTP/IP layer) 414 may ensurereliable delivery of signaling messages between the RAN node 128/130 andthe AMF 132 based, in part, on the IP protocol, supported by the IPlayer 413. The L2 layer 412 and the L1 layer 411 may refer tocommunication links (e.g., wired or wireless) used by the RAN node128/130 and the AMT 132 to exchange information.

The RAN node 128/130 and the AMY 132 may utilize an N2 interface toexchange control plane data via a protocol stack comprising the L1 layer411, the L2 layer 412, the IP layer 413, the SCTP layer 414, and theS1-AP layer 415.

FIG. 5 is an illustration of a user plane protocol stack in accordancewith some aspects. in this aspect, a user plane 500 is shown as acommunications protocol stack between the UE 102, the RAN node 128 (oralternatively, the RAN node 130), and the UPF 134. The user plane 500may utilize at least some of the same protocol layers as the controlplane 400. For example, the UE 102 and the RAN node 128 may utilize anNR radio interface to exchange user plane data via a protocol stackcomprising the PHY layer 401, the MAC layer 402, the RLC layer 403, thePDCP layer 404, and the Service Data Adaptation Protocol (SDAP) layer416. The SDAP layer 416 may, in some aspects, execute a mapping betweena Quality of Service (QoS) flow and a data radio bearer (DRB), and amarking of both DL and UL packets with a QoS flow ID (QFI). In someaspects, an IP protocol stack 513 can be located above the SDAP 416. Auser datagram protocol (UDP)/transmission control protocol (TCP) stack520 can be located above the IP stack 513. A session initiation protocol(SIP) stack 522 can be located above the UDP/TCP stack 520, and can beused by the UE 102 and the UPF 134.

The General Packet Radio Service (GPRS) Tunneling Protocol for the userplane (GTP-U) layer 504 may be used for carrying user data within the 5Gcore network 120 and between the radio access network 110 and the 5Gcore network 120. The user data transported can be packets in IPv4,IPv6, or PPP formats, for example. The UDP and IP security (UDP/IP)layer 503 may provide checksums for data integrity, port numbers foraddressing different functions at the source and destination, andencryption and authentication on the selected data flows. The RAN node128/130 and the UPF 134 may utilize an N3 interface to exchange userplane data via a protocol stack comprising the L1 layer 411, the L2layer 412, the UDP/1P layer 503, and the GTP-U layer 504. As discussedabove with respect to FIG. 4 , NAS protocols support the mobility of theUE 101 and the session management procedures to establish and maintainIP connectivity between the UE 101 and the UPF 134.

FIG. 6 is a block diagram illustrating components, according to someexample aspects, able to read instructions from a machine-readable orcomputer-readable medium (e.g., a non-transitory machine-readablestorage medium) and perform any one or more of the methodologiesdiscussed herein. Specifically, FIG. 6 shows a diagrammaticrepresentation of hardware resources 600 including one or moreprocessors (or processor cores) 610, one or more memory/storage devices620, and one or more communication resources 630, each of which may becommunicatively coupled via a bus 640. For aspects in which nodevirtualization (e.g., NFV) is utilized, a hypervisor 602 may be executedto provide an execution environment for one or more network slicesand/or sub-slices to utilize the hardware resources 600

The processors 610 (e.g., a central processing unit (CPU), a reducedinstruction set computing (RISC) processor, a complex instruction setcomputing (CISC) processor, a graphics processing unit (GPU), a digitalsignal processor (DSP) such as a baseband processor, an applicationspecific integrated circuit (ASIC), a radio-frequency integrated circuit(RFIC), another processor, or any suitable combination thereof) mayinclude, for example, a processor 612 and a processor 614.

The memory/storage devices 620 may include main memory, disk storage, orany suitable combination thereof. The memory/storage devices 620 mayinclude, but are not limited to, any type of volatile or non-volatilememory such as dynamic random access memory (DRAM), static random-accessmemory (SRAM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), Flashmemory, solid-state storage, etc.

The communication resources 630 may include interconnection or networkinterface components or other suitable devices to communicate with oneor more peripheral devices 604 or one or more databases 606 via anetwork 608. For example, the communication resources 630 may includewired communication components (e.g., for coupling via a UniversalSerial Bus (USB)), cellular communication components, NFC components,Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components,and other communication components.

Instructions 650 may comprise software, a program, an application, anapplet, an app, or other executable code for causing at least any of theprocessors 610 to perform any one or more of the methodologies discussedherein. The instructions 650 may reside, completely or partially, withinat least one of the processors 610 (e.g., within the processor's cachememory), the memory/storage devices 620, or any suitable combinationthereof. Furthermore, any portion of the instructions 650 may betransferred to the hardware resources 600 from any combination of theperipheral devices 604 or the databases 606. Accordingly, the memory ofprocessors 610, the memory/storage devices 620, the peripheral devices604, and the databases 606 are examples of computer-readable andmachine-readable media.

FIG. 7 is an illustration of an initial access procedure 700 includingPRACH preamble retransmission in accordance with some aspects. Referringto FIG. 7 , the initial access procedure 700 can start with operation702, when initial synchronization can take place. For example, the UE101 can receive a primary synchronization signal and a secondarysynchronization signal to achieve the initial synchronization. In someaspects, the initial synchronization at operation 702 can be performedusing one or more SS blocks received within an SS burst set. Atoperation 704, the UE 101 can receive system information, such as one ormore system information blocks (SIBS) and/or master information blocks(MIBs).

At operation 706 through 714, a random access procedure can take place.More specifically, at operation 706, a PRACH preamble transmission cantake place as message 1 (Msg1). At operation 710, UE 101 can receive arandom access response (RAR) message, which can be random accessprocedure message 2 (Msg2). In Msg2, the node (e.g., gNB) 111 canrespond with random access radio network temporary identifier (RA-RNTI),which can be calculated from the preamble resource (e.g., time andfrequency allocation).

In some aspects, UE 101 can be configured to perform one or moreretransmissions of the PRACH preamble at operation 708, when the RAR isnot received or detected within a preconfigured or predefined timewindow. The PRACH preamble retransmission can take place with powerramping, as explained herein below, so that the transmission power isincreased until the random-access response is received.

At operation 712, UE 101 can transmit a random access procedure message3 (Msg3), which can include a radio resource control (RRC) connectionrequest message. At operation 714, a random access procedure message 4(Msg4) can be received by the UE 101, which can include an RRCconnection setup message, carrying the cell radio network temporaryidentifier (CRNTI) used for subsequent communication between the UE 101and the node 111.

In some aspects, user equipment and communication nodes operating onmmWave bands can experience phase noise (PN) and carrier frequencyoffset (CFO) due to, e.g., transmitter and receiver frequency oscillatormismatch. More specifically, phase noise can be generated from noise inthe active components in lossy elements, which can be up convert it tothe carrier frequency resulting in inferior transmit/receiveperformance. In some aspects, the PN and CFO impact may become severefor 5G communication systems operating in high frequency bands (e.g.,because is greater than 6 GHz). The Phase Tracking Reference Signal(PT-RS) can be configured using one or more of the techniques describedherein to track and mitigate the effects of phase noise and phaseshifting at a communication device transceiver circuitry.

In some aspects, for a cyclic prefix OFDM (CP-OFDM) waveform, the PT-RSand data can be multiplexed in Frequency Division Multiplexing (FDM)manner, with some resource elements being used for PT-RS. For DFT-s-OFDMwaveform, the PT-RS can be inserted before the DFT. FIG. 8 illustratesan example of chunk-based PT-RS for a DFT-s-OFDM waveform, in accordancewith some aspects. Referring to FIG. 8 , the DFT-s-OFDM waveform 802 caninclude data 804 and PT-RS 806. The PT-RS 806 can be spread out inmultiple groups or chunks, and each chunk can be of size 2 symbols(other chunk sizes can be used as well). The waveform 802 can betransformed using DFT operation 808, followed by resource mapping,inverse fast Fourier transform (IFFT), and cyclic prefix addition atoperation 810.

Techniques disclosed herein can be used for PT-RS configuration forDFT-s-OFDM waveform and CP-OFDM waveform, as well as for PT-RSassociation table configuration for both CP-OFDM and DFT-s-OFDMwaveforms.

PT-RS Configuration

In some aspects, the PT-RS can be used for phase shift compensationresulting from the phase noise and CFO for both a DFT-s-OFDM waveformand a CP-OFDM waveform. In aspects when the phase shift is low, thePT-RS can be disabled so as to reduce its overhead.

In some aspects, In an embodiment, the dynamic presence and/or timeand/or frequency domain density and/or chunk size of PT-RS can bedetermined based on at least one of the following techniques:

(a) Based on a number of front-loaded demodulation reference signal(DM-RS) symbols, where the symbols are fixed (e.g., either the 3rd or4th symbol) for PDSCH or in front of the PUSCH symbols;

(b) Based on a number of additional DM-RS symbols, where the symbols areafter at least one symbol of PDSCH or PUSCH; and

(c) Based on whether time domain Orthogonal Cover Code (TD-OCC) is usedfor DM-RS or other reference signal, such as Channel State informationReference Signal (CSI-RS). In some aspects, the TD-OCC can be configuredby control signaling (such as DCI) and can be set to ON or OFF. In someaspects, if TD-OCC is enabled, PT-RS with a first time domain densitycan be used (e.g., time domain density of one as listed in the tablebelow), and if TD-OCC is disabled, PT-RS with a second time domaindensity can be used (e.g. time domain density of two as listed in thetable below).

In some aspects, the above associations (including the associationslisted in the tables below) can be pre-defined and/or configured byhigher layer signaling or Downlink Control Information (DCI) and/orrecommended by the UE.

In some aspects, if TD-OCC is enabled and is used with two front-loadedDM-RS symbols (which means the phase shift between two symbols is notsignificant), a low density PT-RS (e.g., time density of one) or noPT-RS can be used. Table 2 below illustrates one example of associationtable.

TABLE 2 an example of association table between PT-RS density and numberof front-loaded DM-RS Number of front-loaded DM-RS symbols PT-RS timedomain density 1 Time domain density set 1, e.g.{every symbol, every2^(nd) symbol, every 4^(th) symbol} 2 Time domain density set 2,e.g.{every 2^(nd) symbol, every 4^(th) symbol}

In another aspect, if the additional DM-RS symbol is used, the Dopplerfrequency offset may be large. Consequently, the PT-RS can betransmitted at every symbol and the size of chunk PT-RS for DFT-s-OFDMcan be increased. Table 3 below illustrates one example for theassociation table definitions.

TABLE 3 an example association table between PT-RS density and number ofadditional DM-RS Number of additional DM-RS symbol(s) PT-RS time domaindensity 0 Time domain density set 1, e.g.{every symbol, every 2^(nd)symbol, every 4^(th) symbol} 1 Time domain density set 2, e.g.{everysymbol} 2 Time domain density set 3, e.g.{every symbol}

In some aspects, the time domain density of PT-RS can be selected basedon the above association tables as well as from one or morecorresponding time density sets, which can be determined based onmodulation and coding scheme (MCS), bandwidth (BW), and/or subcarrierspacing (SCS). Some example PT-RS density tables based on MCS, BW,and/or SCS are illustrated hereinbelow.

In some aspects, if TD-OCC with length 4 is configured for CSI-RS, thePT-RS may be disabled since the phase shift between the 4 symbols maynot be significant.

FIG. 9 illustrates an example slot 900 with PT-RS and DM-RS symbolcollision, in accordance with some aspects. Referring to FIG. 9 , slot900 can include PDCCH 902, front-loaded DM-RS 904, followed by PUSCHwith additional DM-RS 906. PT-RS 908, 910, 912, 914, and 916 can beconfigured after the front-loaded DM-RS 904. As illustrated in FIG. 9 ,a resource element (RE) (or REs) for PT-RS 912 collides with a RE (orREs) within the additional DM-RS 906. In this case, one or more of thetechniques described in connection with FIG. 10 , FIG. 11 , and FIG. 12can be used to handle the PT-RS collision.

FIG. 10 illustrates an example slot 1000 with PT-RS collision handlingusing PT-RS puncturing, in accordance with some aspects. Referring toFIG. 10 , slot 1000 can include PDCCH 1002, front-loaded DM-RS 1004,followed by PUSCH with additional DM-RS 1006. PT-RS 1008, 1010, 1012,1014, and 1016 can be configured after the front-loaded DM-RS 1004. Asillustrated in FIG. 10 , a RE (or REs) for PT-RS 1012 collides with a RE(or REs) within the additional DM-RS 1006. In some aspects, the PT-RS1012 at the collided RE (or REs) can be punctured as illustrated in FIG.10 . In this regard, the additional DM-RS 1006 is transmitted in aspectswhen the PT-RS collides with the additional DM-RS.

FIG. 11 illustrates an example slot 1100 with PT-RS collision handlingusing a resource element shifting, in accordance with some aspects.Referring to FIG. 11 , slot 1100 can include PDCCH 1102, front-loadedDM-RS 1104, followed by PUSCH with additional DM-RS 1106. PT-RS 1108,1110, 1112A, 1114, and 1116 can be configured after the front-loadedDM-RS 1104. As illustrated in FIG. 11 , a RE (or REs) for PT-RS 1112Acollides with a RE (or REs) within the additional DM-RS 1106. In someaspects, the PT-RS 1012A at the collided RE (or REs) can be shifted tothe neighboring symbol/subcarriers as illustrated in FIG. 11 . In thisregard, PT-RS 1112B is transmitted in place of the collided PT-RS 1112A.

FIG. 12 illustrates an example slot 1200 with PT-RS collision handlingusing shifting of multiple resource elements, in accordance with someaspects. Referring to FIG. 12 , slot 1200 can include PDCCH 1202,front-loaded DM-RS 1204, followed by PUSCH with additional DM-RS 1206.PT-RS 1208A, 1210A, 1212A, 1214A, and 1216A can be configured after thefront-loaded DM-RS 1204. As illustrated in FIG. 12 , a RE (or REs) forPT-RS 1212A collides with a RE (or REs) within the additional DM-RS1206. In some aspects, the entire PT-RS (including PT-RS 1208A, 1210A,1212A, 1214A, and 1216A) can be shifted to the neighboringsymbol/subcarriers as illustrated in FIG. 12 . In this regard, PT-RS1208B, 1210B, 1212B, 1214B, and 1216B are transmitted in place of PT-RS1208A, 1210A, 1212A, 1214A, and 1216A.

In some aspects, selection of PT-RS collision handling techniquesillustrated in FIG. 10 -FIG. 12 can be pre-defined or configured byhigher layer signaling, DCI, or determined by the number of additionalsymbols and/or the density of the PT-RS. In an example, if the timedomain density of PT-RS is to map the PT-RS in every symbol, whencollision occurs, the PT-RS handling techniques illustrated in FIG. 10can be used.

In some aspects, the above collision handling techniques can also beapplied to aspects when PT-RS is collided with other reference signal orchannels, such as Tracking Reference Signal (TRS), channel stateinformation-reference signal (CSI-RS), PDCCH, PUCCH, and so forth.

FIG. 13 illustrates an example slot 1300 with PT-RS multiplexing when anadditional DM-RS symbol is used, in accordance with some aspects.Referring to FIG. 13 , slot 1300 can include PDCCH 1302, front-loadedDM-RS 1304, followed by PUSCH with additional DM-RS 1306. PT-RS 1308 and1310 can be configured after the front-loaded DM-RS 1304, and PT-RS1312, 1314, and 1316 can be configured after the additional DM-RS 1306.

In some aspects, when additional DM-RS is enabled, the PT-RS can bemapped to k0 number of symbols after the front-loaded DM-RS and k1number of symbol after the additional DM-RS, where k0 and k1 can bepre-defined or configured by higher layer signaling or DCI or determined based on the density of PT-RS. FIG. 13 illustrates one examplewhen parameter k0=1 and parameter k1=1 and the PT-RS density is every2nd symbol. In some aspects, this technique can also be used to identifythe time position of the PT-RS for a DFT-s-OFDM waveform.

In some aspects, for chunk-based PT-RS for a DFT-s-OFDM waveform, thesymbol index S_(j)(n) of each chunk j with chunk size N can bedetermined by the number of DFT points N_(DFT) (which can be based onthe allocated bandwidth) as well as the number of chunks K (which can bedetermined based on the MCS and/or bandwidth). In one example, thesymbol index can be calculated as follows:

${{S_{j}(n)} = {\left\lfloor \frac{N_{DFT}}{K + 1} \right\rfloor + n}},{n = 0},1,\ldots\mspace{14mu},{N - 1.}$

Alternatively, the starting symbol of chunk based PT-RS can beconfigured by higher layer signaling, DCI or pre-defined in a wirelessspecification, or a combination thereof.

Association Table Definition

In some aspects, the dynamic presence and time/frequency density of thePT-RS for CP-OFDM can be determined by the SCS, MCS, and/or BW. In thisregard, pre-defined association tables for determining thetime/frequency density of the PT-RS based on SCS, MCS, and/or BW can beconfigured. In some aspects, one association table can be defined foridle mode, where the highest density of PT-RS can be used. Table 4 andTable 5 illustrate one example for association table definitions.

TABLE 4 an example for association table of idle mode time domaindensity for PT-RS for CP-OFDM MCS Time domain density MCS >= 0 PT-RSshould be mapped to every symbol

TABLE 5 an example for association table of idle mode frequency domaindensity for PT-RS for CP-OFDM Frequency domain BW density Number ofallocated RB >= 0 1 or 2 RE/RB/Symbol

In another aspect, the number of chunks and the size of chunk and thetime domain density for PT-RS for DFT-s-OFDM can be determined based onSCS and/or BW and/or MCS. For idle mode, the PT-RS with highest densitycan be used, where the size of chunk and the number of chunks can be thelargest, the value of which can be pre-defined. Table 6 illustrates oneexample for the association table for chunk-based PT-RS for DFT-s-OFDMwaveform, where aj, bj, cj, Ncj and Scj, j=1, 2, can be pre-defined orconfigured by DCI, higher layer signaling, or recommended by the UE.

TABLE 6 an example for association table of chunk-based PT-RS Number ofConfiguration chunks Size of chunk SCS < a1 and/or BW < b1 and/or NoPT-RS No PT-RS MCS < c1 SCS >= a1 and SCS < a2; and/or Nc1 Sc1 BW >= b1and BW < b2; and/or MCS >= c1 and MCS < c2 SCS >= a2 and/or BW >= b2 Nc2Sc2 and/or MCS >= c2

In some aspects, a user equipment (UE) can include circuitry todetermine the dynamic presence and time and frequency density of PT-RSfor both CP-OFDM and DFT-s-OFDM waveform using one or more of thetechniques disclosed herein. For CP-OFDM, the dynamic presence and timeand frequency density of PT-RS can be determined at least by one of theconfigurations of number of front-loaded DMRS symbols, number ofadditional DMRS symbols and length of TD-OCC for DMRS, and/or CSI-RS.For CP-OFDM, the candidate time and frequency density set of PT-RS canbe determined at least by one of the configurations of number offront-loaded DMRS symbols, number of additional DMRS symbols, and lengthof TD-OCC for DMRS and/or CSI-RS.

For DFT-s-OFDM, the dynamic presence and number of chunks and the sizeof chunks and time domain density of PT-RS can be determined at least byone of the configurations of number of front-loaded DMRS symbols, numberof additional DMRS symbols, and length of TD-OCC for DMRS and/or CSI-RS.For DFT-s-OFDM, the candidate time and number of chunks, the size ofchunks and time domain set of PT-RS can be determined at least by one ofthe configurations of number of front-loaded DMRS symbols, number ofadditional DMRS symbols and length of TD-OCC for DMRS and/or CSI-RS.

In some aspects, an association table can be pre-defined and/orconfigured by higher layer signaling and/or recommended by the UE. Insome aspects, when collision between the additional DM-RS and PT-RSoccurs, at the collided REs, the PT-RS can be punctured. In someaspects, when collision between the additional DM-RS and PT-RS occurs,at the collided REs, the PT-RS can be shifted to neighboring symbols orsubcarriers. In some aspects, when collision between the additionalDIVI-RS and PT-RS occurs, all the PT-RS can be shifted to neighboringsymbols or subcarriers. In some aspects, one or more of the aboveoptions can be pre-defined or configured by higher layer signaling orrecommended by UE or determined by the number of additional DMRS symbolsand/or the density of PT-RS.

In some aspects, the number of chunks and size of chunk for PT-RS forDFT-s-OFDM can be determined by the allocated bandwidth (BW) and/orModulation and Coding Scheme (MCS) and/or subcarrier spacing (SCS). Insome aspects when CP-OFDM waveforms are used, for idle mode, singletime/frequency density of PT-RS can be used, which can be pre-defined.In some aspects when DFT-s-OFDM waveforms are used, for idle mode,single number of chunks and/or size of chunk and/or time density ofPT-RS can be used, which can be pre-defined.

In some aspects, when additional DM-RS is enabled, the PT-RS can bemapped to the k0 symbol after the front-loaded DM-RS and k1 symbol afterthe additional DM-RS, where k0 and k1 can be pre-defined or configuredby higher layer signaling or DCI or determined based on the density ofPT-RS.

In some aspects, for chunk-based PT-RS for DFT-s-OFDM waveforms, thesymbol index of each chunk can be determined by the number of DFT pointsas well as the number of chunks. In some aspects, for chunk-based PT-RSfor DFT-s-OFDM waveforms, the symbol index of each chunk can bepredefined or configured by higher layer signaling or DCL

In some aspects, for CP-OFDM waveforms, time domain PT-RS pattern can beevery symbol, every other symbol and every 4th symbol, which can bedetermined by the MCS in a bandwidth part. Table 7 illustrates how thetime domain pattern of PT-RS can be determined.

TABLE 7 PT-RS time domain pattern for CP-OFDM Scheduled MCS Time domaindensity (L_(PT-RS)) I_(MCS) < ptrs-MCS₁ PT-RS is not present ptrs-MCS1 ≤I_(MCS) < ptrs-MCS2 4 ptrs-MCS2 ≤ I_(MCS) < ptrs-MCS3 2 ptrs-MCS3 ≤ptrs-MCS4 1

In the above table, imcs is the MCS index which can be provided by DCI,and ptrs-MCSi are our various MCS thresholds which can be provided byother configuration signaling such as higher layer signaling (e.g., RRCsignaling). The second column in Table 7 is the time domain density ofPT-RS.

In some aspects, the frequency domain density of PT-RS can be every 2resource blocks (RBs) or every 4 RBs, and can be determined based on,e.g., the number of allocated resource block (RBs) (Nrb). Table 8illustrates how the frequency domain pattern of PT-RS can be determined.

TABLE 8 PT-RS frequency domain pattern for CP-OFDM Frequency domaindensity Scheduled bandwidth (K_(PT-RS)) N_(RB) < N_(RB0) PT-RS is notpresent N_(RB0) ≤ N_(RB) < N_(RB1) 2 N_(RB1) ≤ N_(RB) 4

In the above table, NRB is the number of allocated resource blocks whichcan be configured by DCI, and NH resource block number thresholds whichcan be provided by other configuration signaling such as higher layersignaling (e.g., RRC signaling).

For DFT-s-OFDM, the PT-RS pattern, e.g. number of PT-RS groups, PT-RSgroup size as shown in FIG. 8 and the time domain pattern, can also bedetermined by the MCS and allocated bandwidth in a bandwidth part (BWP).

In adaptive Hybrid Automatic Repeat request (HARQ), it is possible thatthe gNB can indicate to the UE to keep the Transport Block (TB) sizewith a new modulation order and/or new allocated RB. Then such a groupof modulation order and number of RB may not be associated with an MC Sdefined in the MCS table. More specifically, the gNB can indicate areserved MCS in DCI, where the reserved MCS only indicates modulationorder without indicating a coding scheme. In this case, a redundancyversion indicator in DCI can instruct the UE to retransmit uplink datain connection with a HARQ process. Techniques disclosed herein can beused to determine the PT-RS pattern (e.g., PT-RS time domain pattern andPT-RS frequency domain pattern) during such retransmission of uplinkdata when adaptive HARQ is used.

In some aspects in connection with an adaptive retransmission, themodulation order can be independently indicated by the gNB. The numberof RBs can also be changed. In this case, the exact MCS may not be foundin the MCS association table (e.g., as provided in the above Tables).The following techniques can be used to determine the PT-RS pattern inretransmission.

In some aspects, N_RB_j can be denoted as the number of RBs in the jthtransmission in a HARQ process. In the kth retransmission, for CP-OFDM,the frequency domain pattern can be determined based on one or more ofthe following options:

Option 1: based on a current number of RBs (e.g., N_RB_k+1) for use inthe current (k+1) retransmission;

Option 2: based on the number of RBs in a particular previoustransmission, e.g. N_RB_1 (the first or initial transmission of theuplink data) or N_RB_k (the previous re-transmission of the uplinkdata); and

Option 3: based on a function of number of RBs in previous transmissionand current transmission, e.g. min{N_RB_1, N_RB_2, . . . , N_RB_k+1}(i.e., the minimum from the number of resource blocks used for all priortransmissions and retransmissions of the uplink data), or max{N_RB_1,N_RB_2, . . . , N_RB_k+1} (i.e., the maximum from the number of resourceblocks used for all prior transmissions and retransmissions of theuplink data).

In some aspects, use of one or more of the above options can bepre-defined by the spec or configured by higher layer signaling or DCI.

In some aspects, MCS_j can be denoted as the MCS in the jth transmissionin a HARQ process. In the kth retransmission, for CP-OFDM, the frequencydomain density of PT-RS can be determined based on one or more of thefollowing options:

Option 1a: based on current MCS (i.e., MCS_k+1) indicated in DCI if theMCS is valid in the MCS association table (e.g., Table 7 above);

Option 1b: based on current MCS estimated according to modulation order,number of RBs and TB size for the current transmission;

Option 2: based on an MCS indicated or estimated in a particularprevious transmission, e.g. MCS_1 (the first or initial transmission ofthe uplink data) or MCS_k (the prior retransmission of the uplink data);

Option 3: based on a function of MCS in one or more previoustransmissions and the current transmission, e.g. min{MCS_1, MCS_2, . . ., MCS_k+1}, or max{MCS_1, MCS_2, MCS_k+1};

Option 4: based on the lowest (or highest) MCS with modulation orderindicated by adaptive retransmission; and

Option 5: based on the predetermined density corresponding to the MCS ofthe adaptive HARQ.

In some aspects, use of one or more of the above options can bepre-defined by the spec or configured by higher layer signaling or DCI.

In some aspects in connection with option 1b, the MCS can be estimatedaccording to the modulation order and the coding rate in the currenttransmission. The estimated MCS can be selected from the MCS with thesame modulation order. Then the estimated MCS can be indicated as MCS_xor x+1 when the coding rate of MCS_x<current coding rate<coding rate ofMCS_x+1.

In some aspects in connection with option 5, there can be one ormultiple pre-defined PT-RS patterns for retransmission, the pattern usedfor the retransmission can be determined by the bandwidth part and/orthe redundancy version indicated by the DCI.

In some aspects, when a MCS offset is indicated in the DCI, the MCS usedto determine the PT-RS pattern can include the MC S offset as well.

In some aspects associated with DFT-s-OFDM waveforms, the same optionsabove can also be used to determine the number of RBs and MCS, which canbe used to determine the number of PT-RS groups, the size of a PT-RSgroup and/or the time domain density of PT-RS.

In some aspects, when the PT-RS is configured to be used in adaptiveretransmission, the UE can expect the gNB to configure the MCS definedin the MCS table, e.g. 0<=MCS<=28. In this aspect, the PT-RS pattern forthe retransmission can be determined by the MCS and resource allocationfor current slot.

In some aspects, for DL or UL semi-persistent scheduling (SPS) basedtransmission and uplink grant free transmission, the MCS offset which isused to adjust the MCS to assist the PT-RS pattern selection can beassumed to be 0, and the antenna port of PT-RS can be assumed to beassociated with a particular DM-RS antenna port, e.g. with the lowestantenna port index.

In some aspects, a UE can include circuitry to determine the PT-RS inadaptive Hybrid Automatic Repeat request (HARQ) mode. In some aspects,the frequency domain pattern of PT-RS can be determined by the number ofresource blocks in the retransmission. In some aspects, the frequencydomain pattern of PT-RS can be determined by the number of resourceblocks in a previous transmission or a previous retransmission. In someaspects, the frequency domain pattern of PT-RS can be determined by thenumber of resource blocks used in a sub-set or all previous transmissionand a current retransmission. in some aspects, the time domain patternof PT-RS can be determined by the MCS or estimated MCS in a currentretransmission, or in a previous transmission or retransmission. In someaspects, the time domain pattern of PT-RS can be determined by the MCSor estimated MCS in a sub-set of all the previous transmission and acurrent retransmission. In some aspects, a predefined or configuredPT-RS pattern can be used in the retransmission. In some aspects,multiple predefined or configured PT-RS pattern can be used in theretransmission. In some aspects, the PT-RS pattern used a particularretransmission can be determined by the bandwidth part and/or redundancyversion indicated by the DCI. In some aspects, when PT-RS is configuredto be used, the MCS indication can be the valid MCS in the MCS table. Insome aspects, for DL or UL semi-persistent scheduling (SPS) basedtransmission and uplink grant free transmission, the value of the MCSoffset which is used to adjust the MCS to assist the PT-RS patternselection can be predefined. In some aspects, for UL SPS-basedtransmission and uplink grant free transmission, the PT-RS antenna portassociation can be predefined.

Resource Mapping of PT-RS

In some aspects, when CP-OFDM waveforms are used, time domain PT-RSpattern can be every symbol, every other symbol and every 4th symbol,which can be determined by the MCS in a bandwidth part. Additionally,there can be one or two PT-RS antenna ports and one or two codewordsindicated in configuration signaling (e.g., DCI) for each transmission.Techniques disclosed herein can be used to determine which MCS is usedfor determination of the resource mapping pattern of PT-RS.

In some aspects, frequency domain offset of PT-RS including the ResourceElement (RE) offset and Resource Block (RB) offset can be determined byUE ID, and/or higher layer control signaling. Techniques disclosedherein can be used to define the frequency offset of PT-RS for differentcases triggered by different radio network temporary identifier (RNTI).

In some aspects, Tracking Reference Signal (TRS) can be used for timeand frequency offset tracking. Techniques disclosed herein can be usedto multiplex the TRS and PT-RS.

MCS Selection for PT-RS Time Domain Pattern

In some aspects, up to two PDSCH codewords (CWs) can be configured fordownlink transmissions, and up to one PUSCH codeword can be configuredfor uplink transmissions, where different codewords can use differentMCS. In aspects when DCI configures two codewords, the UE can decode totransmit blocks which can be mapped to differentmultiple-input-multiple-output (MIMO) layers. In some aspects, the DCIcan further indicate PT-RS antenna ports that can be used for PT-RStransmission. In some aspects, the DCI can indicate one or two PT-RSantenna ports, where each PT-RS antenna port can include an associationto a DM-RS antenna port.

In some aspects, the PT-RS time domain density (e.g., no transmission,transmission on every symbol, transmission on every other symbol, ortransmission on every 4th symbol) can be determined by the MCS and theMCS threshold (which is configured by higher layer signaling). Inaspects when DCI configures two codewords, there can be an MCS in eachcodeword.

FIG. 14 illustrates example PT-RS time domain pattern determination 1400for two codewords and one PT-RS antenna port, in accordance with someaspects. In some aspects, if one PT-RS antenna port (e.g., 1402) is usedtogether with two codewords (e.g., 1404 and 1406), the PT-RS pattern canbe based on the highest MCS (e.g., MCS0), since the codeword withhighest MCS includes a DM-RS antenna port associated with the PT-RS.Alternatively, the PT-RS time domain pattern can be determined by thelowest MCS or the average MCS of the two codewords.

FIG. 15 illustrates example PT-RS time domain pattern determination 1500for two codewords and two PT-RS antenna ports, in accordance with someaspects. FIG. 16 illustrates example PT-RS time domain patterndetermination 1600 for two codewords and two PT-RS antenna ports, inaccordance with some aspects.

In another aspect, if two PT-RS antenna ports are used and two codewordsare used, the PT-RS pattern of one antenna port can be determined by oneof the MCS in the two codewords, which is predefined or determined bythe antenna port association between the PT-RS antenna port and theDM-RS antenna port. Alternatively, the PT-RS time domain pattern of oneantenna port can be determined by the two MCS, e.g. the maximum orminimal or averaged MCS.

Referring to FIG. 15 , PT-RS antenna port 1502 is associated with theDM-RS antenna port 0 for codeword 1506. Therefore, the time domainpattern for transmitting PT-RS via antenna port 1502 can be determinedbased on MCS0 for codeword 1506. Similarly, PT-RS antenna port 1504 isassociated with the DM-RS antenna port 3 for codeword 1508. Therefore,the time domain pattern for transmitting PT-RS via antenna port 1504 canbe determined based on MCS1 for codeword 1508.

Referring to FIG. 16 , PT-RS antenna port 1602 is associated with theDM-RS antenna port 0 for codeword 1606. Therefore, the time domainpattern for transmitting PT-RS via antenna port 1602 can be determinedbased on MCS0 for codeword 1606. Similarly, PT-RS antenna port 1604 isassociated with the DM-RS antenna port 2 for codeword 1606. Therefore,the time domain pattern for transmitting PT-RS via antenna port 1604 canbe determined also based on MCS0 for codeword 1606.

FIG. 17 illustrates example PT-RS time domain pattern determination 1700for a single codewords and two PT-RS antenna ports, in accordance withsome aspects.

In some aspects, two PT-RS antenna ports can be used (e.g., 1702 and1704) with a single codeword (e.g., 1706). In this aspect, the PT-RSpattern can be determined by the MCS (e.g., MCS0) of the codeword (e.g.,1706). Alternatively, an MCS offset can be indicated in the DCI for eachof the PT-RS antenna ports independently, to, e.g., reflect differentSINR in different antenna ports. In aspects when MCS offset is indicatedfor each PT-RS antenna port (e.g., offset0 and offset1), the time domainpattern for PT-RS can be determined based on MCS0 associated with thecodeword and the corresponding offset associated with each PT-RS antennaport.

PT-RS Frequency Domain Offset (e.g., RB Offset) for Different Types ofRNTI

In some aspects, the PT-RS RE offset in a RB for PDSCH triggered by acell specific RNTI (C-RNTI) based PDCCH can be determined based on theC-RNTI. There can be different types of used in a wireless communicationsystem, such as random access RNTI (RA-RNTI), system information RNTI(SI-RNTI), paging RNTI (P-RNTI), multimedia broadcast multicast service(MBMS) RNTI (M-RNTI), and so forth. In some aspects, the PT-RS can beinserted in every other RB or every 4th RB, or another RB offset can beprovided (e.g., by DCI or higher layer signaling).

In some aspects, the RE and/or RB offset for the PDSCH triggered byPDCCH with different types of RNTI, e.g. RA-RNTI, SI-RNTI, P-RNTI andM-RNTI, can be determined by the corresponding RNTI or can be fixed(e.g., the first subcarrier as used by the DM-RS, determined based onthe virtual cell ID or cell ID, or can be configured by the higher layersignaling). In some aspects, the time domain pattern of PT-RStransmission for the transmission of common control messages can bepredefined.

In some aspects associated with connected mode UEs that have beenconfigured with MCS and/or bandwidth threshold to adjust the PT-RSpattern, to receive the signal for other RNTI except the C-RNTI, adefault PT-RS threshold defined in a pre-configured association tablecan be used.

Multiplexing of TRS and PT-RS

FIG. 18 illustrates an example slot 1800 with PT-RS and trackingreference signal (TRS) collision, in accordance with some aspects.Referring to FIG. 18 , slot 1800 can include transmission of PT-RS 1804subsequent to the DM-RS transmission, as well as transmission of TRS1802. As illustrated in FIG. 18 , RE 1806 can be on overlapping REbetween the TRS and the PT-RS data.

In some aspects, the UE may or may not be configured with bothmulti-slot or multi-symbol based TRS and PT-RS. If the multi-slot andmulti-symbol TRS is enabled, the PT-RS may not be used. Alternatively,if the PT-RS is enabled, the multi-slot and multi-symbol TRS may not beconfigured. Instead, the TRS may only be transmitted in a single slot orin a single symbol.

In another aspect, if collision between TRS and PT-RS occurs, asillustrated in FIG. 18 , the PT-RS of the colliding REs may bepunctured. Alternatively the colliding subcarrier or the whole TRS canbe punctured.

In some aspects, a UE can include circuitry to determine the time andfrequency resource mapping pattern for phase tracking reference signal(PT-RS). In some aspects, if one PT-RS antenna port is used and 2codewords are used, the PT-RS pattern is based on the highest MCS. Insome aspects, if one PT-RS antenna port is used and 2 codewords areused, the PT-RS time domain pattern is determined by the lowest MCS orthe average MCS of the two codewords. In some aspects, if two PT-RSantenna ports are used and two codewords are used, the PT-RS pattern ofone antenna port can be determined by one of the MCS in the twocodewords, which is predefined or determined by the antenna portassociation between the PT-RS antenna port and the DMRS antenna port. Insome aspects, if two PT-RS antenna ports are used and two codewords areused, the PT-RS time domain pattern of one antenna port can bedetermined by the maximum or minimal or averaging MCS from the two MCSfor two codewords. In some aspects, if two PT-RS antenna ports are usedand a single codeword is used, the PT-RS pattern could be determined bythe MCS of this codeword. In some aspects, if two PT-RS antenna portsare used and a single codeword is used, the MCS offset can be indicatedin the DCI for each PT-RS antenna port independently or jointly.

In some aspects, the RE and/or RB offset for the PDSCH triggered byPDSCH with different types of RNTI, e.g. RA-RNTI, SI-RNTI, P-RNTI andM-RNTI, is deter mined by the corresponding RNTI or cell ID or virtualcell ID or it can be fixed. In some aspects, the UE may not beconfigured with both multi-slot or multi-symbol based TRS and PT-RS. Insome aspects, if the multi-slot and multi-symbol TRS is enabled, thePT-RS may not be used. In some aspects, if the PT-RS is enabled, themulti-slot and multi-symbol TRS may not be configured and onlysingle-symbol or single-slot TRS can be used. In some aspects, ifcollision between TRS and PT-RS occurs, the PT-RS of the colliding REscan be punctured. In some aspects, if collision between TRS and PT-RSoccurs, the TRS of the colliding REs or the whole symbol or slot ormulti-slot of TRS can be punctured.

FIG. 19 illustrates generally a flowchart of example functionalities ofa method 1900 which can be performed in a wireless architecture inconnection with PT-RS configuration, in accordance with some aspects.Referring to FIG. 19 , the method 1900 can start at operation 1902 whendownlink control information (DCI) (e.g., 190A) received from a basestation (e.g., 111) can be decoded. The DCI (190A) can include amodulation coding scheme (MCS) index and physical uplink shared channel(PDSCH) allocation.

At operation 1904, a demodulation reference signal (DM-RS) (e.g., 904,906) can be encoded for transmission to the base station within aplurality of DM-RS symbols based on the PUSCH allocation.

At operation 1906, a phase tracking reference signal (PT-RS) time domaindensity and frequency domain density can be determined based on the MCSindex and a number count of the DM-RS symbols for the DM-RS transmission(e.g., the number of symbols used for the transmission of DM-RS 1904and/or 1906).

At operation 1908, the PT-RS (e.g., 192A and 908-916) can be encoded fortransmission using a plurality of PT-RS symbols based on the determinedPT-RS time domain density and frequency domain density.

FIG. 20 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a next generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or a userequipment (UE), in accordance with some aspects. In alternative aspects,the communication device 2000 may operate as a standalone device or maybe connected (e.g., networked) to other communication devices.

Circuitry (e.g., processing circuitry) is a collection of circuitsimplemented in tangible entities of the device 2000 that includehardware (e.g., simple circuits, gates, logic, etc.). Circuitrymembership may be flexible over time. Circuitries include members thatmay, alone or in combination, perform specified operations whenoperating. In an example, hardware of the circuitry may be immutablydesigned to carry out a specific operation (e.g., hardwired). In anexample, the hardware of the circuitry may include variably connectedphysical components (e.g., execution units, transistors, simplecircuits, etc.) including a machine-readable medium physically modified(e.g., magnetically, electrically, moveable placement of invariantmassed particles, etc.) to encode instructions of the specificoperation.

In connecting the physical components, the underlying electricalproperties of a hardware constituent are changed, for example, from aninsulator to a conductor or vice versa. The instructions enable embeddedhardware (e.g., the execution units or a loading mechanism) to createmembers of the circuitry in hardware via the variable connections tocarry out portions of the specific operation when in operation.Accordingly, in an example, the machine-readable medium elements arepart of the circuitry or are communicatively coupled to the othercomponents of the circuitry when the device is operating. In an example,any of the physical components may be used in more than one member ofmore than one circuitry. For example, under operation, execution unitsmay be used in a first circuit of a first circuitry at one point in timeand reused by a second circuit in the first circuitry, or by a thirdcircuit in a second circuitry at a different time. Additional examplesof these components with respect to the device 2000 follow.

In some aspects, the device 2000 may operate as a standalone device ormay be connected (e.g., networked) to other devices. In a networkeddeployment, the communication device 2000 may operate in the capacity ofa server communication device, a client communication device, or both inserver-client network environments. in an example, the communicationdevice 2000 may act as a peer communication device in peer-to-peer (P2P)(or other distributed) network environment. The communication device2000 may be a UE, eNB, PC, a tablet PC, a STB, a PDA, a mobiletelephone, a smart phone, a web appliance, a network router, switch orbridge, or any communication device capable of executing instructions(sequential or otherwise) that specify actions to be taken by thatcommunication device. Further, while only a single communication deviceis illustrated, the term “communication device” shall also be taken toinclude any collection of communication devices that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein, such as cloudcomputing, software as a service (SaaS), and other computer clusterconfigurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a communication device-readable medium. In anexample, the software, when executed by the underlying hardware of themodule, causes the hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Softwaremay accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Communication device (e.g., UE) 2000 may include a hardware processor2002 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 2004, a static memory 2006, and mass storage 2007 (e.g., harddrive, tape drive, flash storage, or other block or storage devices),some or all of which may communicate with each other via an interlink(e.g., bus) 2008.

The communication device 2000 may further include a display device 2010,an alphanumeric input device 2012 (e.g., a keyboard), and a userinterface (UI) navigation device 2014 (e.g., a mouse). In an example,the display device 2010, input device 2012 and UI navigation device 2014may be a touch screen display. The communication device 2000 mayadditionally include a signal generation device 2018 (e.g., a speaker),a network interface device 2020, and one or more sensors 2021, such as aglobal positioning system (GPS) sensor, compass, accelerometer, or othersensor. The communication device 2000 may include an output controller2028, such as a serial (e.g., universal serial bus (USB), parallel, orother wired or wireless (e.g., infrared (IR), near field communication(NFC), etc.) connection to communicate or control one or more peripheraldevices (e.g., a printer, card reader, etc.).

The storage device 2007 may include a communication device-readablemedium 2022, on which is stored one or more sets of data structures orinstructions 2024 (e.g., software) embodying or utilized by any one ormore of the techniques or functions described herein. In some aspects,registers of the processor 2002, the main memory 2004, the static memory2006, and/or the mass storage 2007 may be, or include (completely or atleast partially), the device-readable medium 2022, on which is storedthe one or more sets of data. structures or instructions 2024, embodyingor utilized by any one or more of the techniques or functions describedherein. In an example, one or any combination of the hardware processor2002, the main memory 2004, the static memory 2006, or the mass storage2016 may constitute the device-readable medium 2022.

As used herein, the term “device-readable medium” is interchangeablewith “computer-readable medium” or “machine-readable medium”. While thecommunication device-readable medium 2022 is illustrated as a singlemedium, the term “communication device-readable medium” may include asingle medium or multiple media (es., a centralized or distributeddatabase, and/or associated caches and servers) configured to store theone or more instructions 2024.

The term “communication device-readable medium” may include any mediumthat is capable of storing, encoding, or carrying instructions (e.g.,instructions 2024) for execution by the communication device 2000 andthat cause the communication device 2000 to perform any one or more ofthe techniques of the present disclosure, or that is capable of storing,encoding or carrying data structures used by or associated with suchinstructions. Non-limiting communication device-readable medium examplesmay include solid-state memories, and optical and magnetic media.Specific examples of communication device-readable media may include:non-volatile memory, such as semiconductor memory devices (e.g.,Electrically Programmable Read-Only Memory (EPROM), ElectricallyErasable Programmable Read-Only Memory (EEPROM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM andDVD-ROM disks. In some examples, communication device-readable media mayinclude non-transitory communication device-readable media. In someexamples, communication device-readable media may include communicationdevice-readable media that is not a transitory propagating signal.

The instructions 2024 may further be transmitted or received over acommunications network 2026 using a transmission medium via the networkinterface device 2020 utilizing any one of a number of transferprotocols (e.g., frame relay, internet protocol (IP), transmissioncontrol protocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards, a LongTerm Evolution (LTE) family of standards, a Universal MobileTelecommunications System (UMTS) family of standards, peer-to-peer (P2P)networks, among others. In an example, the network interface device 2020may include one or more physical jacks (e.g., Ethernet, coaxial, orphone jacks) or one or more antennas to connect to the communicationsnetwork 2026. In an example, the network interface device 2020 mayinclude a plurality of antennas to wirelessly communicate using at leastone of single-input multiple-output (SIMO), MIMO, or multiple-inputsingle-output (MISO) techniques. In some examples, the network interfacedevice 2020 may wirelessly communicate using Multiple User MIMOtechniques.

The term “transmission medium” shall be taken to include any intangiblemedium that is capable of storing, encoding or carrying instructions forexecution by the communication device 2000, and includes digital oranalog communications signals or other intangible medium to facilitatecommunication of such software. In this regard, a transmission medium inthe context of this disclosure is a device-readable medium.

ADDITIONAL NOTES AND EXAMPLES

Example 1 is an apparatus of a user equipment (UE), the apparatuscomprising: processing circuitry configured to: decode downlink controlinformation (DCI) from a base station, the DCI including a modulationcoding scheme (MCS) index and physical uplink shared channel (PUSCH)allocation; encode a demodulation reference signal (DM-RS) fortransmission to the base station within a plurality of DM-RS symbolsbased on the PUSCH allocation; determine a phase tracking referencesignal (PT-RS) time domain density based on the MCS index and a numbercount of the DM-RS symbols for transmission of the DM-RS; and encode thePT-RS for transmission using a plurality of PT-RS symbols based on thePT-RS time domain density; and memory coupled to the processingcircuitry, the memory configured to store the MCS index.

In Example 2, the subject matter of Example 1 includes, wherein theplurality of DM-RS symbols comprises one or both of front-loaded DM-RSsymbols and additional DM-RS symbols.

In Example 3, the subject matter of Example 2 includes, wherein thefront-loaded DM-RS symbols comprise one or two DM-RS symbols, and theadditional DM-RS symbols comprise 0, 1, or 2 DM-RS symbols.

In Example 4, the subject matter of Examples 1-3 includes, wherein thePT-RS time domain density includes no PT-RS symbol transmission, PT-RSsymbol transmission on every symbol, PT-RS symbol transmission on everysecond symbol, or PT-RS symbol transmission on every fourth symbol.

In Example 5, the subject matter of Examples 1-4 includes, wherein theDCI includes physical downlink shared channel (PDSCH) allocation, andthe processing circuitry is configured to: decode PT-RS originating fromthe base station, the PT-RS received with downlink data based on thePDSCH allocation.

In Example 6, the subject matter of Examples 1-5 includes, wherein theprocessing circuitry is configured to: determine PT-RS frequency domaindensity or PT-RS chunk size based on the number count of the DM-RSsymbols for DM-RS transmission.

In Example 7, the subject matter of Examples 1-6 includes, wherein theDCI further includes an indicator whether a time domain orthogonal covercode (TD-OCC) will be used at the UE, and the processing circuitry isfurther to: determine one or both of the PT-RS time domain density andPT-RS frequency domain density based on the TD-OCC indicator.

In Example 8, the subject matter of Examples 2-7 includes, wherein theprocessing circuitry is configured to: determine that at least one ofthe additional DM-RS symbols will collide with at least one of the PT-RSsymbols at a common resource element; and puncture the at least onePT-RS symbol that is determined to collide with the at least oneadditional DM-RS symbol at the common resource element.

In Example 9, the subject matter of Examples 2-8 includes, wherein theprocessing circuitry is configured to: determine that at least one ofthe additional DM-RS symbols will collide with at least one of the PT-RSsymbols at a common resource element; and shift the at least one PT-RSsymbol that is determined to collide with the at least one additionalDM-RS symbol to a neighboring symbol.

In Example 10, the subject matter of Examples 2-9 includes, wherein theprocessing circuitry is configured to: determine that at least one ofthe additional DM-RS symbols will collide with at least one of the PT-RSsymbols at a common resource element; and re-map the PT-RS symbols fortransmission in neighboring symbols.

In Example 11, the subject matter of Examples 1-10 includes, wherein theprocessing circuitry is configured to: decode control informationsignaling configuring the DM-RS symbols as front-loaded DM-RS symbolsand additional DM-RS symbols for the DM-RS transmission, the controlinformation further including a first PT-RS density indicator and asecond PT-RS density indicator; map at least a first PT-RS symbol of theplurality of PT-RS symbols after a first number of symbols subsequent tothe front-loaded DM-RS symbols, the first number of symbols based on thefirst PT-RS density indicator; and map at least a second PT-RS symbol ofthe plurality of PT-RS symbols after a second number of symbolssubsequent to the additional DM-RS symbols, the second number of symbolsbased on the second PT-RS density indicator.

In Example 12, the subject matter of Examples 1-11 includes, wherein thePT-RS is encoded for transmission via a digital Fourier transform spreadorthogonal frequency division multiplexing (DFT-s-OFDM) waveform, andthe DCI further includes a starting symbol indicator for chunk-basedtransmission of the PT-RS symbols.

In Example 13, the subject matter of Examples 1-12 includes, wherein thePT-RS is encoded for transmission via a digital Fourier transform spreadorthogonal frequency division multiplexing (DFT-s-OFDM) waveform, andthe DCI further configures one or more of the following: a sub-carrierspacing (SCS) threshold, a bandwidth (BW) threshold, and a MCSthreshold.

In Example 14, the subject matter of Example 13 includes, wherein theprocessing circuitry is configured to: determine one or both of a numbercount of chunks and chunk size for transmitting the PT-RS symbols basedon one or more of the following: the configured SCS, BW, and MCSthresholds.

In Example 15, the subject matter of Examples 1-14 includes, whereinprocessing circuitry is configured to: decode a redundancy versionindicator using the DCI, the redundancy version indicator associatedwith re-transmission of previously transmitted uplink data for a hybridautomatic repeat request (HARQ) process.

In Example 16, the subject matter of Example 15 includes, wherein theMCS index is a reserved MC S index indicating a modulation order withoutindicating a modulation coding scheme, and wherein processing circuitryis configured to: determine a MCS index used in a prior transmission ofthe uplink data; determine a time domain PT-RS density for a secondPT-RS associated with data re-transmission; and encode the uplink datafor re-transmission with the second PT-RS at the determined PT-RSdensity.

In Example 17, the subject matter of Example 16 includes, whereinprocessing circuitry is configured to: determine a frequency domainPT-RS density for a second PT-RS based on a number count of resourceblocks allocated for the re-transmission; and encode the uplink data forre-transmission with the second PT-RS at the determined frequency domainPT-RS density.

In Example 18, the subject matter of Example 17 includes, whereinprocessing circuitry is configured to: determine the frequency domainPT-RS density for the second PT-RS based on a number count of resourceblocks allocated for a prior transmission of the uplink data.

In Example 19, the subject matter of Examples 16-18 includes, whereinprocessing circuitry is configured to: determine the time domain PT-RSdensity for the second PT-RS based on a current MCS index indicated inthe DCI.

In Example 20, the subject matter of Examples 16-19 includes, whereinprocessing circuitry is configured to: determine the time domain PT-RSdensity for the second PT-RS based on an MCS index associated with aninitial transmission of the uplink data.

In Example 21, the subject matter of Examples 16-20 includes, whereinprocessing circuitry is configured to: determine the time domain PT-RSdensity for the second PT-RS based on a subset of MCS indices associatedwith a plurality of prior transmissions of the uplink data.

In Example 22, the subject matter of Examples 1-21 includes, wherein theDCI includes scheduling of at least two physical downlink shared channel(PDSCH) codewords mapped to different multiple-input-multiple-output(MIMO) layers, each of the codeword associated with a corresponding MCSindicator.

In Example 23, the subject matter of Example 22 includes, wherein theprocessing circuitry is configured to: determine a density pattern forthe PT-RS based on the corresponding MCS indicators associated with theat least two PDSCH codewords; and encode the PT-RS for transmissionusing at least one PT-RS antenna port and based on the determineddensity pattern.

In Example 24, the subject matter of Example 23 includes, wherein theprocessing circuitry is configured to: selects a highest MCS indicatorof the corresponding MCS indicators; and determine the density patternbased on the highest MCS indicator.

In Example 25, the subject matter of Examples 23-24 includes, whereinthe at least one PT-RS antenna port comprises two PT-RS antenna portsindicated by the DCI.

In Example 26, the subject matter of Examples 23-25 includes, whereinthe processing circuitry is configured to: selects a lowest MCSindicator of the corresponding MCS indicators; and determine the densitypattern based on the lowest MCS indicator.

In Example 27, the subject matter of Examples 22-26 includes, whereinthe DCI further indicates two PT-RS antenna ports for PT-RStransmission, each of the PT-RS antenna ports associated with acorresponding DM-RS antenna port for transmitting a DM-RS, and whereinthe processing circuitry is configured to: determine a density patternfor the PT-RS based on one of the corresponding MCS indicatorsassociated with the at least two PDSCH codewords, or based on anassociation between the PT-RS antenna ports and the DM-RS antenna ports;and encode the PT-RS for transmission using one of the two PT-RS antennaport and based on the determined density pattern.

In Example 28, the subject matter of Examples 1-27 includes, wherein theprocessing circuitry is configured to: decode signaling encoded with aradio network temporary identifier (RNTI); determine a type of the RNTIbased on the decoded signaling; and select a pre-defined density as thePT-RS time domain density, the pre-defined density based on thedetermined type of the RNTI.

In Example 29, the subject matter of Example 28 includes, wherein theprocessing circuitry is configured to: cease encoding of the PT-RS fortransmission based on the type of the RNTI.

In Example 30, the subject matter of Examples 1-29 includes, transceivercircuitry coupled to the processing circuitry; and, one or more antennascoupled to the transceiver circuitry.

Example 31 is an apparatus of a base station, the apparatus comprising:processing circuitry configured to: encode downlink control information(DCI) for transmission to a user equipment (UE), the DCI including amodulation coding scheme (MCS) index and physical uplink shared channel(PUSCH) allocation; decode front-loaded demodulation reference signal(DM-RS) symbols and additional DM-RS symbols received based on the PUSCHallocation; decode a phase tracking reference signal (PT-RS) receivedwith uplink data, the PT-RS having PT-RS density based on the MCS indexand a number count of the front-loaded DM-RS symbols and the additionalDM-RS symbols; and track phase noise during decoding of the uplink datausing the PT-RS; and memory coupled to the processing circuitry, thememory configured to store the MCS index.

In Example 32, the subject matter of Example 31 includes, wherein thefront-loaded DM-RS symbols comprise one or two DM-RS symbols, and theadditional DM-RS symbols comprise 0, 1, or 2 DM-RS symbols.

In Example 33, the subject matter of Examples 31-32 includes, whereinthe PT-RS density includes PT-RS symbol transmission on every symbol,PT-RS symbol transmission on every second symbol, or PT-RS symboltransmission on every fourth symbol.

In Example 34, the subject matter of Examples 31-33 includes, whereinthe processing circuitry configured to: encode the DCI to furtherincludes an indicator whether a time domain orthogonal cover code(TD-OCC) will be used at the UE, and wherein the PT-RS density isfurther based on the TD-OCC indicator.

In Example 35, the subject matter of Examples 31-34 includes, whereinthe base station is an evolved Node-B (eNB) or a next generation Node-B(gNB).

In Example 36, the subject matter of Examples 31-35 includes,transceiver circuitry coupled to the processing circuitry; and, one ormore antennas coupled to the transceiver circuitry.

Example 37 is a computer-readable storage medium that storesinstructions for execution by one or more processors of a user equipment(UE), the instructions to configure the one or more processors to causethe UE to: decode downlink control information (DCI) from a basestation, the DCI including a modulation coding scheme (MCS) index andphysical uplink shared channel (PUSCH) allocation; encode a demodulationreference signal (DM-RS) for transmission to the base station within aplurality of DM-RS symbols based on the PUSCH allocation; determine aphase tracking reference signal (PT-RS) time domain density andfrequency domain density based on the MCS index and a number count ofthe DM-RS symbols for the DM-RS transmission; and encode the PT-RS fortransmission using a plurality of PT-RS symbols based on the PT-RS timedomain density and the PT-RS frequency domain density.

In Example 38, the subject matter of Example 37 includes, wherein theplurality of symbols comprises one or both of front-loaded DM-RS symbolsand additional DM-RS symbols.

In Example 39, the subject matter of Example 38 includes, wherein thefront-loaded DM-RS symbols comprise one or two DM-RS symbols, and theadditional DM-RS symbols comprise 0,1, or 2 DM-RS symbols.

In Example 40, the subject matter of Examples 37-39 includes, whereinthe PT-RS time domain density includes no PT-RS symbol transmission,PT-RS symbol transmission on every symbol, PT-RS symbol transmission onevery second symbol, or PT-RS symbol transmission on every fourthsymbol.

In Example 41, the subject matter of Examples 37-40 includes, whereinthe PT-RS frequency domain density includes no PT-RS symboltransmission, PT-RS symbol transmission every 2 resource blocks, orPT-RS symbol transmission every 4 resource blocks.

In Example 42, the subject matter of Examples 37-41 includes, whereinthe instructions further configure the one or more processors to causethe UE to: determine the PT-RS frequency domain density or PT-RS chunksize based on a number count of the plurality of DM-RS symbols used forthe DM-RS transmission.

In Example 43, the subject matter of Examples 37-42 includes, whereinthe DCI further includes an indicator whether a time domain orthogonalcover code (TD-OCC) will be used at the UE, and the instructions furtherconfigure the one or more processors to cause the UE to: determine oneor both of the PT-RS time domain density and the PT-RS frequency domaindensity based on the TD-OCC indicator.

Example 44 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 1-43.

Example 45 is an apparatus comprising means to implement of any ofExamples 1-43.

Example 46 is a system to implement of any of Examples 1-43.

Example 47 is a method to implement of any of Examples 1-43.

Although an aspect has been described with reference to specific exampleaspects, it will be evident that various modifications and changes maybe made to these aspects without departing from the broader scope of thepresent disclosure. Accordingly, the specification and drawings are tobe regarded in an illustrative rather than a restrictive sense. Theaccompanying drawings that form a part hereof show, by way ofillustration, and not of limitation, specific aspects in which thesubject matter may be practiced. The aspects illustrated are describedin sufficient detail to enable those skilled in the art to practice theteachings disclosed herein. Other aspects may be utilized and derivedtherefrom, such that structural and logical substitutions and changesmay be made without departing from the scope of this disclosure. ThisDetailed Description, therefore, is not to be taken in a limiting sense,and the scope of various aspects is defined only by the appended claims,along with the full range of equivalents to which such claims areentitled.

Such aspects of the inventive subject matter may be referred to herein,individually and/or collectively, merely for convenience and withoutintending to voluntarily limit the scope of this application to anysingle aspect or inventive concept if more than one is in factdisclosed. Thus, although specific aspects have been illustrated anddescribed herein, it should be appreciated that any arrangementcalculated to achieve the same purpose may be substituted for thespecific aspects shown. This disclosure is intended to cover any and alladaptations or variations of various aspects. Combinations of the aboveaspects, and other aspects not specifically described herein, will beapparent to those of skill in the art upon reviewing the abovedescription.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. in addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in a single aspect for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed aspects require more featuresthan are expressly recited in each claim. Rather, as the followingclaims reflect, inventive subject matter lies in less than all featuresof a single disclosed aspect. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate aspect.

What is claimed is:
 1. An apparatus, comprising: at least one processorconfigured to cause a user equipment (UE) to: encode a demodulationreference signal (DM-RS) for transmission to a base station within aplurality of DM-RS symbols, wherein the plurality of DM-RS symbolscomprises front-loaded DM-RS symbols; determine a phase trackingreference signal (PT-RS) time domain density based on a modulationcoding scheme (MCS) index; encode the PT-RS for transmission using aplurality of PT-RS symbols based on the PT-RS time domain density; andmap a first PT-RS symbol of the plurality of PT-RS symbols such that thefirst PT-RS symbol occurs a first number of symbols subsequent to thefront-loaded DM-RS symbols, wherein the first number of symbols is basedon the PT-RS time domain density.
 2. The apparatus of claim 1, whereinthe plurality of DM-RS symbols comprises additional DM-RS symbols, andwherein the at least one processor is further configured to cause the UEto: map a second PT-RS symbol of the plurality of PT-RS symbols suchthat the second PT-RS symbol occurs a second number of symbolssubsequent to the additional DM-RS symbols, wherein the second number ofsymbols is based on the PT-RS time domain density.
 3. The apparatus ofclaim 1, wherein the PT-RS time domain density is determined based onthe MCS index and a number count of the DM-RS symbols for transmissionof the DM-RS.
 4. The apparatus of claim 3, wherein the at least oneprocessor is further configured to cause the UE to: determine that atleast one of the additional DM-RS symbols will collide with at least oneof the PT-RS symbols at a common resource element; and puncture the atleast one PT-RS symbol that is determined to collide with the at leastone additional DM-RS symbol at the common resource element.
 5. Theapparatus of claim 3, wherein the at least one processor is furtherconfigured to cause the UE to: determine that at least one of theadditional DM-RS symbols will collide with at least one of the PT-RSsymbols at a common resource element; and shift the at least one PT-RSsymbol that is determined to collide with the at least one additionalDM-RS symbol to a neighboring symbol.
 6. The apparatus of claim 3,wherein the at least one processor is further configured to cause the UEto: determine that at least one of the additional DM-RS symbols willcollide with at least one of the PT-RS symbols at a common resourceelement; and re-map the PT-RS symbols for transmission in neighboringsymbols.
 7. The apparatus of claim 1, wherein the PT-RS is encoded fortransmission via a digital Fourier transform spread orthogonal frequencydivision multiplexing (DFT-s-OFDM) waveform, wherein the at least oneprocessor is further configured to cause the UE to decode downlinkcontrol information (DCI) from the base station, and wherein the DCIfurther configures one or more of the following: a sub-carrier spacing(SCS) threshold, a bandwidth (BW) threshold, and an MCS threshold. 8.The apparatus of claim 7, wherein the at least one processor is furtherconfigured to cause the UE to: determine one or both of a number countof chunks and chunk size for transmitting the PT-RS symbols based on oneor more of the following: the configured SCS threshold, the configuredBW threshold, and the configured MCS threshold.
 9. The apparatus ofclaim 1, wherein the at least one processor is further configured tocause the UE to: decode downlink control information (DCI) from the basestation; and decode a redundancy version indicator using the DCI,wherein the redundancy version indicator is associated withre-transmission of previously transmitted uplink data for a hybridautomatic repeat request (HARD) process.
 10. The apparatus of claim 9,wherein the MCS index is a reserved MCS index indicating a modulationorder without indicating a modulation coding scheme, and wherein the atleast one processor is further configured to cause the UE to: determinean MCS index used in a prior transmission of the uplink data; determinea second time domain PT-RS density for a second PT-RS associated withdata re-transmission; and encode the uplink data for re-transmissionwith the second PT-RS at the determined second PT-RS density.
 11. Theapparatus of claim 1, wherein the at least one processor is furtherconfigured to decode downlink control information (DCI) from the basestation, and wherein the DCI includes scheduling of at least twophysical downlink shared channel (PDSCH) codewords mapped to differentmultiple-input-multiple-output (MIMO) layers, wherein each of the atleast two PDSCH codewords is associated with a corresponding MCSindicator.
 12. The apparatus of claim 11, wherein the at least oneprocessor is further configured to cause the UE to: determine a densitypattern for the PT-RS based on the corresponding MCS indicatorsassociated with the at least two PDSCH codewords; and encode the PT-RSfor transmission using at least one PT-RS antenna port and based on thedetermined density pattern.
 13. The apparatus of claim 12, wherein theat least one processor is further configured to cause the UE to: selectan extreme valued MCS indicator of the corresponding MCS indicators; anddetermine the density pattern based on the extreme-valued MCS indicator.14. The apparatus of claim 11, wherein the at least one processor isfurther configured to cause the UE to decode downlink controlinformation (DCI) from the base station, wherein the DCI furtherindicates two PT-RS antenna ports for PT-RS transmission, wherein eachof the PT-RS antenna ports is associated with a corresponding DM-RSantenna port for transmitting a DM-RS, and wherein the at least oneprocessor is further configured to cause the UE to: determine a densitypattern for the PT-RS based on one of the corresponding MCS indicatorsassociated with the at least two PDSCH codewords, or based on anassociation between the PT-RS antenna ports and the DM-RS antenna ports;and encode the PT-RS for transmission using one of the two PT-RS antennaport and based on the determined density pattern.
 15. An apparatus,comprising: at least one processor configured to cause a base stationto: decode front-loaded demodulation reference signal (DM-RS) symbolsand additional DM-RS symbols received, wherein the plurality of DM-RSsymbols comprises front-loaded DM-RS symbols; and decode a phasetracking reference signal (PT-RS) received, wherein the PT-RS has aPT-RS time domain density in accordance with a modulation coding scheme(MCS), wherein a first PT-RS symbol occurs a first number of symbolssubsequent to the front-loaded DM-RS symbols, wherein the first numberof symbols is based on the PT-RS time domain density.
 16. The apparatusof claim 15, wherein the PT-RS density indicates PT-RS symbol receptionon every symbol, or PT-RS symbol reception on every second symbol, orPT-RS symbol reception on every fourth symbol.
 17. The apparatus ofclaim 15, wherein the at least one processor is further configured tocause the base station to: encode downlink control information (DCI) tofurther include an indicator that indicates whether a time domainorthogonal cover code (TD-OCC) will be used at the UE, and wherein thePT-RS density is further based on the TD-OCC indicator.
 18. Anon-transitory computer-readable storage medium storing programinstructions for execution by one or more processors of a user equipment(UE), wherein the program instructions, when executed by the one or moreprocessors, cause the UE to: encode a demodulation reference signal(DM-RS) for transmission to thea base station within a plurality ofDM-RS symbols, wherein the plurality of DM-RS symbols comprisesfront-loaded DM-RS symbols; determine a phase tracking reference signal(PT-RS) symbol time domain position based on a modulation coding scheme(MCS) index and a position of the DM-RS symbols for transmission of theDM-RS; and encode the PT-RS for transmission using a plurality of PT-RSsymbols based on the determined PT-RS symbol time domain position. 19.The non-transitory computer-readable storage medium of claim 18, whereinthe program instructions, when executed by the one or more processors,further cause the UE to: determine a PT-RS time domain density based onthe MCS index; and map a first PT-RS symbol of the plurality of PT-RSsymbols so that the first PT-RS symbol occurs a first number of symbolssubsequent to the front-loaded DM-RS symbols, wherein the first numberof symbols is based on the PT-RS time domain density.
 20. Thenon-transitory computer-readable storage medium of claim 18, wherein theplurality of DM-RS symbols comprises additional DM-RS symbols, whereinthe program instructions, when executed by the one or more processors,further cause the UE to: map a second PT-RS symbol of the plurality ofPT-RS symbols so that the second PT-RS symbol occurs a second number ofsymbols subsequent to the additional DM-RS symbols, wherein the secondnumber of symbols is based on the PT-RS time domain density.